Involved Source Filesformat.goformat_rfc3339.gosleep.gosys_unix.gotick.go Package time provides functionality for measuring and displaying time.
The calendrical calculations always assume a Gregorian calendar, with
no leap seconds.
# Monotonic Clocks
Operating systems provide both a “wall clock,” which is subject to
changes for clock synchronization, and a “monotonic clock,” which is
not. The general rule is that the wall clock is for telling time and
the monotonic clock is for measuring time. Rather than split the API,
in this package the Time returned by [time.Now] contains both a wall
clock reading and a monotonic clock reading; later time-telling
operations use the wall clock reading, but later time-measuring
operations, specifically comparisons and subtractions, use the
monotonic clock reading.
For example, this code always computes a positive elapsed time of
approximately 20 milliseconds, even if the wall clock is changed during
the operation being timed:
start := time.Now()
... operation that takes 20 milliseconds ...
t := time.Now()
elapsed := t.Sub(start)
Other idioms, such as [time.Since](start), [time.Until](deadline), and
time.Now().Before(deadline), are similarly robust against wall clock
resets.
The rest of this section gives the precise details of how operations
use monotonic clocks, but understanding those details is not required
to use this package.
The Time returned by time.Now contains a monotonic clock reading.
If Time t has a monotonic clock reading, t.Add adds the same duration to
both the wall clock and monotonic clock readings to compute the result.
Because t.AddDate(y, m, d), t.Round(d), and t.Truncate(d) are wall time
computations, they always strip any monotonic clock reading from their results.
Because t.In, t.Local, and t.UTC are used for their effect on the interpretation
of the wall time, they also strip any monotonic clock reading from their results.
The canonical way to strip a monotonic clock reading is to use t = t.Round(0).
If Times t and u both contain monotonic clock readings, the operations
t.After(u), t.Before(u), t.Equal(u), t.Compare(u), and t.Sub(u) are carried out
using the monotonic clock readings alone, ignoring the wall clock
readings. If either t or u contains no monotonic clock reading, these
operations fall back to using the wall clock readings.
On some systems the monotonic clock will stop if the computer goes to sleep.
On such a system, t.Sub(u) may not accurately reflect the actual
time that passed between t and u. The same applies to other functions and
methods that subtract times, such as [Since], [Until], [Time.Before], [Time.After],
[Time.Add], [Time.Equal] and [Time.Compare]. In some cases, you may need to strip
the monotonic clock to get accurate results.
Because the monotonic clock reading has no meaning outside
the current process, the serialized forms generated by t.GobEncode,
t.MarshalBinary, t.MarshalJSON, and t.MarshalText omit the monotonic
clock reading, and t.Format provides no format for it. Similarly, the
constructors [time.Date], [time.Parse], [time.ParseInLocation], and [time.Unix],
as well as the unmarshalers t.GobDecode, t.UnmarshalBinary.
t.UnmarshalJSON, and t.UnmarshalText always create times with
no monotonic clock reading.
The monotonic clock reading exists only in [Time] values. It is not
a part of [Duration] values or the Unix times returned by t.Unix and
friends.
Note that the Go == operator compares not just the time instant but
also the [Location] and the monotonic clock reading. See the
documentation for the Time type for a discussion of equality
testing for Time values.
For debugging, the result of t.String does include the monotonic
clock reading if present. If t != u because of different monotonic clock readings,
that difference will be visible when printing t.String() and u.String().
# Timer Resolution
[Timer] resolution varies depending on the Go runtime, the operating system
and the underlying hardware.
On Unix, the resolution is ~1ms.
On Windows version 1803 and newer, the resolution is ~0.5ms.
On older Windows versions, the default resolution is ~16ms, but
a higher resolution may be requested using [golang.org/x/sys/windows.TimeBeginPeriod].zoneinfo.gozoneinfo_goroot.gozoneinfo_read.gozoneinfo_unix.go
Code Examples
package main
import (
"fmt"
"time"
)
var c chan int
func handle(int) {}
func main() {
select {
case m := <-c:
handle(m)
case <-time.After(10 * time.Second):
fmt.Println("timed out")
}
}
package main
import (
"fmt"
"time"
)
func main() {
t := time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC)
fmt.Printf("Go launched at %s\n", t.Local())
}
package main
import (
"fmt"
"time"
)
func expensiveCall() {}
func main() {
t0 := time.Now()
expensiveCall()
t1 := time.Now()
fmt.Printf("The call took %v to run.\n", t1.Sub(t0))
}
package main
import (
"fmt"
"math"
"time"
)
func main() {
positiveDuration := 5 * time.Second
negativeDuration := -3 * time.Second
minInt64CaseDuration := time.Duration(math.MinInt64)
absPositive := positiveDuration.Abs()
absNegative := negativeDuration.Abs()
absSpecial := minInt64CaseDuration.Abs() == time.Duration(math.MaxInt64)
fmt.Printf("Absolute value of positive duration: %v\n", absPositive)
fmt.Printf("Absolute value of negative duration: %v\n", absNegative)
fmt.Printf("Absolute value of MinInt64 equal to MaxInt64: %t\n", absSpecial)
}
package main
import (
"fmt"
"time"
)
func main() {
h, _ := time.ParseDuration("4h30m")
fmt.Printf("I've got %.1f hours of work left.", h.Hours())
}
package main
import (
"fmt"
"time"
)
func main() {
u, _ := time.ParseDuration("1s")
fmt.Printf("One second is %d microseconds.\n", u.Microseconds())
}
package main
import (
"fmt"
"time"
)
func main() {
u, _ := time.ParseDuration("1s")
fmt.Printf("One second is %d milliseconds.\n", u.Milliseconds())
}
package main
import (
"fmt"
"time"
)
func main() {
m, _ := time.ParseDuration("1h30m")
fmt.Printf("The movie is %.0f minutes long.", m.Minutes())
}
package main
import (
"fmt"
"time"
)
func main() {
u, _ := time.ParseDuration("1µs")
fmt.Printf("One microsecond is %d nanoseconds.\n", u.Nanoseconds())
}
package main
import (
"fmt"
"time"
)
func main() {
d, err := time.ParseDuration("1h15m30.918273645s")
if err != nil {
panic(err)
}
round := []time.Duration{
time.Nanosecond,
time.Microsecond,
time.Millisecond,
time.Second,
2 * time.Second,
time.Minute,
10 * time.Minute,
time.Hour,
}
for _, r := range round {
fmt.Printf("d.Round(%6s) = %s\n", r, d.Round(r).String())
}
}
package main
import (
"fmt"
"time"
)
func main() {
m, _ := time.ParseDuration("1m30s")
fmt.Printf("Take off in t-%.0f seconds.", m.Seconds())
}
package main
import (
"fmt"
"time"
)
func main() {
fmt.Println(1*time.Hour + 2*time.Minute + 300*time.Millisecond)
fmt.Println(300 * time.Millisecond)
}
package main
import (
"fmt"
"time"
)
func main() {
d, err := time.ParseDuration("1h15m30.918273645s")
if err != nil {
panic(err)
}
trunc := []time.Duration{
time.Nanosecond,
time.Microsecond,
time.Millisecond,
time.Second,
2 * time.Second,
time.Minute,
10 * time.Minute,
time.Hour,
}
for _, t := range trunc {
fmt.Printf("d.Truncate(%6s) = %s\n", t, d.Truncate(t).String())
}
}
package main
import (
"fmt"
"time"
)
func main() {
loc := time.FixedZone("UTC-8", -8*60*60)
t := time.Date(2009, time.November, 10, 23, 0, 0, 0, loc)
fmt.Println("The time is:", t.Format(time.RFC822))
}
package main
import (
"fmt"
"time"
)
func main() {
location, err := time.LoadLocation("America/Los_Angeles")
if err != nil {
panic(err)
}
timeInUTC := time.Date(2018, 8, 30, 12, 0, 0, 0, time.UTC)
fmt.Println(timeInUTC.In(location))
}
package main
import (
"fmt"
"time"
)
func main() {
// China doesn't have daylight saving. It uses a fixed 8 hour offset from UTC.
secondsEastOfUTC := int((8 * time.Hour).Seconds())
beijing := time.FixedZone("Beijing Time", secondsEastOfUTC)
// If the system has a timezone database present, it's possible to load a location
// from that, e.g.:
// newYork, err := time.LoadLocation("America/New_York")
// Creating a time requires a location. Common locations are time.Local and time.UTC.
timeInUTC := time.Date(2009, 1, 1, 12, 0, 0, 0, time.UTC)
sameTimeInBeijing := time.Date(2009, 1, 1, 20, 0, 0, 0, beijing)
// Although the UTC clock time is 1200 and the Beijing clock time is 2000, Beijing is
// 8 hours ahead so the two dates actually represent the same instant.
timesAreEqual := timeInUTC.Equal(sameTimeInBeijing)
fmt.Println(timesAreEqual)
}
package main
import (
"fmt"
"time"
)
func main() {
_, month, day := time.Now().Date()
if month == time.November && day == 10 {
fmt.Println("Happy Go day!")
}
}
package main
import (
"fmt"
"time"
)
func main() {
ticker := time.NewTicker(time.Second)
defer ticker.Stop()
done := make(chan bool)
go func() {
time.Sleep(10 * time.Second)
done <- true
}()
for {
select {
case <-done:
fmt.Println("Done!")
return
case t := <-ticker.C:
fmt.Println("Current time: ", t)
}
}
}
package main
import (
"fmt"
"time"
)
func main() {
// See the example for Time.Format for a thorough description of how
// to define the layout string to parse a time.Time value; Parse and
// Format use the same model to describe their input and output.
// longForm shows by example how the reference time would be represented in
// the desired layout.
const longForm = "Jan 2, 2006 at 3:04pm (MST)"
t, _ := time.Parse(longForm, "Feb 3, 2013 at 7:54pm (PST)")
fmt.Println(t)
// shortForm is another way the reference time would be represented
// in the desired layout; it has no time zone present.
// Note: without explicit zone, returns time in UTC.
const shortForm = "2006-Jan-02"
t, _ = time.Parse(shortForm, "2013-Feb-03")
fmt.Println(t)
// Some valid layouts are invalid time values, due to format specifiers
// such as _ for space padding and Z for zone information.
// For example the RFC3339 layout 2006-01-02T15:04:05Z07:00
// contains both Z and a time zone offset in order to handle both valid options:
// 2006-01-02T15:04:05Z
// 2006-01-02T15:04:05+07:00
t, _ = time.Parse(time.RFC3339, "2006-01-02T15:04:05Z")
fmt.Println(t)
t, _ = time.Parse(time.RFC3339, "2006-01-02T15:04:05+07:00")
fmt.Println(t)
_, err := time.Parse(time.RFC3339, time.RFC3339)
fmt.Println("error", err) // Returns an error as the layout is not a valid time value
}
package main
import (
"fmt"
"time"
)
func main() {
hours, _ := time.ParseDuration("10h")
complex, _ := time.ParseDuration("1h10m10s")
micro, _ := time.ParseDuration("1µs")
// The package also accepts the incorrect but common prefix u for micro.
micro2, _ := time.ParseDuration("1us")
fmt.Println(hours)
fmt.Println(complex)
fmt.Printf("There are %.0f seconds in %v.\n", complex.Seconds(), complex)
fmt.Printf("There are %d nanoseconds in %v.\n", micro.Nanoseconds(), micro)
fmt.Printf("There are %6.2e seconds in %v.\n", micro2.Seconds(), micro2)
}
package main
import (
"fmt"
"time"
)
func main() {
loc, _ := time.LoadLocation("Europe/Berlin")
// This will look for the name CEST in the Europe/Berlin time zone.
const longForm = "Jan 2, 2006 at 3:04pm (MST)"
t, _ := time.ParseInLocation(longForm, "Jul 9, 2012 at 5:02am (CEST)", loc)
fmt.Println(t)
// Note: without explicit zone, returns time in given location.
const shortForm = "2006-Jan-02"
t, _ = time.ParseInLocation(shortForm, "2012-Jul-09", loc)
fmt.Println(t)
}
package main
import (
"fmt"
"time"
)
func expensiveCall() {}
func main() {
start := time.Now()
expensiveCall()
elapsed := time.Since(start)
fmt.Printf("The call took %v to run.\n", elapsed)
}
package main
import (
"time"
)
func main() {
time.Sleep(100 * time.Millisecond)
}
package main
import (
"fmt"
"time"
)
func statusUpdate() string { return "" }
func main() {
c := time.Tick(5 * time.Second)
for next := range c {
fmt.Printf("%v %s\n", next, statusUpdate())
}
}
package main
import (
"fmt"
"time"
)
func main() {
start := time.Date(2009, 1, 1, 12, 0, 0, 0, time.UTC)
afterTenSeconds := start.Add(time.Second * 10)
afterTenMinutes := start.Add(time.Minute * 10)
afterTenHours := start.Add(time.Hour * 10)
afterTenDays := start.Add(time.Hour * 24 * 10)
fmt.Printf("start = %v\n", start)
fmt.Printf("start.Add(time.Second * 10) = %v\n", afterTenSeconds)
fmt.Printf("start.Add(time.Minute * 10) = %v\n", afterTenMinutes)
fmt.Printf("start.Add(time.Hour * 10) = %v\n", afterTenHours)
fmt.Printf("start.Add(time.Hour * 24 * 10) = %v\n", afterTenDays)
}
package main
import (
"fmt"
"time"
)
func main() {
start := time.Date(2023, 03, 25, 12, 0, 0, 0, time.UTC)
oneDayLater := start.AddDate(0, 0, 1)
dayDuration := oneDayLater.Sub(start)
oneMonthLater := start.AddDate(0, 1, 0)
oneYearLater := start.AddDate(1, 0, 0)
zurich, err := time.LoadLocation("Europe/Zurich")
if err != nil {
panic(err)
}
// This was the day before a daylight saving time transition in Zürich.
startZurich := time.Date(2023, 03, 25, 12, 0, 0, 0, zurich)
oneDayLaterZurich := startZurich.AddDate(0, 0, 1)
dayDurationZurich := oneDayLaterZurich.Sub(startZurich)
fmt.Printf("oneDayLater: start.AddDate(0, 0, 1) = %v\n", oneDayLater)
fmt.Printf("oneMonthLater: start.AddDate(0, 1, 0) = %v\n", oneMonthLater)
fmt.Printf("oneYearLater: start.AddDate(1, 0, 0) = %v\n", oneYearLater)
fmt.Printf("oneDayLaterZurich: startZurich.AddDate(0, 0, 1) = %v\n", oneDayLaterZurich)
fmt.Printf("Day duration in UTC: %v | Day duration in Zürich: %v\n", dayDuration, dayDurationZurich)
}
package main
import (
"fmt"
"time"
)
func main() {
year2000 := time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC)
year3000 := time.Date(3000, 1, 1, 0, 0, 0, 0, time.UTC)
isYear3000AfterYear2000 := year3000.After(year2000) // True
isYear2000AfterYear3000 := year2000.After(year3000) // False
fmt.Printf("year3000.After(year2000) = %v\n", isYear3000AfterYear2000)
fmt.Printf("year2000.After(year3000) = %v\n", isYear2000AfterYear3000)
}
package main
import (
"fmt"
"time"
)
func main() {
t := time.Date(2017, time.November, 4, 11, 0, 0, 0, time.UTC)
text := []byte("Time: ")
text = t.AppendFormat(text, time.Kitchen)
fmt.Println(string(text))
}
package main
import (
"fmt"
"time"
)
func main() {
year2000 := time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC)
year3000 := time.Date(3000, 1, 1, 0, 0, 0, 0, time.UTC)
isYear2000BeforeYear3000 := year2000.Before(year3000) // True
isYear3000BeforeYear2000 := year3000.Before(year2000) // False
fmt.Printf("year2000.Before(year3000) = %v\n", isYear2000BeforeYear3000)
fmt.Printf("year3000.Before(year2000) = %v\n", isYear3000BeforeYear2000)
}
package main
import (
"fmt"
"time"
)
func main() {
d := time.Date(2000, 2, 1, 12, 30, 0, 0, time.UTC)
year, month, day := d.Date()
fmt.Printf("year = %v\n", year)
fmt.Printf("month = %v\n", month)
fmt.Printf("day = %v\n", day)
}
package main
import (
"fmt"
"time"
)
func main() {
d := time.Date(2000, 2, 1, 12, 30, 0, 0, time.UTC)
day := d.Day()
fmt.Printf("day = %v\n", day)
}
package main
import (
"fmt"
"time"
)
func main() {
secondsEastOfUTC := int((8 * time.Hour).Seconds())
beijing := time.FixedZone("Beijing Time", secondsEastOfUTC)
// Unlike the equal operator, Equal is aware that d1 and d2 are the
// same instant but in different time zones.
d1 := time.Date(2000, 2, 1, 12, 30, 0, 0, time.UTC)
d2 := time.Date(2000, 2, 1, 20, 30, 0, 0, beijing)
datesEqualUsingEqualOperator := d1 == d2
datesEqualUsingFunction := d1.Equal(d2)
fmt.Printf("datesEqualUsingEqualOperator = %v\n", datesEqualUsingEqualOperator)
fmt.Printf("datesEqualUsingFunction = %v\n", datesEqualUsingFunction)
}
package main
import (
"fmt"
"time"
)
func main() {
// Parse a time value from a string in the standard Unix format.
t, err := time.Parse(time.UnixDate, "Wed Feb 25 11:06:39 PST 2015")
if err != nil { // Always check errors even if they should not happen.
panic(err)
}
tz, err := time.LoadLocation("Asia/Shanghai")
if err != nil { // Always check errors even if they should not happen.
panic(err)
}
// time.Time's Stringer method is useful without any format.
fmt.Println("default format:", t)
// Predefined constants in the package implement common layouts.
fmt.Println("Unix format:", t.Format(time.UnixDate))
// The time zone attached to the time value affects its output.
fmt.Println("Same, in UTC:", t.UTC().Format(time.UnixDate))
fmt.Println("in Shanghai with seconds:", t.In(tz).Format("2006-01-02T15:04:05 -070000"))
fmt.Println("in Shanghai with colon seconds:", t.In(tz).Format("2006-01-02T15:04:05 -07:00:00"))
// The rest of this function demonstrates the properties of the
// layout string used in the format.
// The layout string used by the Parse function and Format method
// shows by example how the reference time should be represented.
// We stress that one must show how the reference time is formatted,
// not a time of the user's choosing. Thus each layout string is a
// representation of the time stamp,
// Jan 2 15:04:05 2006 MST
// An easy way to remember this value is that it holds, when presented
// in this order, the values (lined up with the elements above):
// 1 2 3 4 5 6 -7
// There are some wrinkles illustrated below.
// Most uses of Format and Parse use constant layout strings such as
// the ones defined in this package, but the interface is flexible,
// as these examples show.
// Define a helper function to make the examples' output look nice.
do := func(name, layout, want string) {
got := t.Format(layout)
if want != got {
fmt.Printf("error: for %q got %q; expected %q\n", layout, got, want)
return
}
fmt.Printf("%-16s %q gives %q\n", name, layout, got)
}
// Print a header in our output.
fmt.Printf("\nFormats:\n\n")
// Simple starter examples.
do("Basic full date", "Mon Jan 2 15:04:05 MST 2006", "Wed Feb 25 11:06:39 PST 2015")
do("Basic short date", "2006/01/02", "2015/02/25")
// The hour of the reference time is 15, or 3PM. The layout can express
// it either way, and since our value is the morning we should see it as
// an AM time. We show both in one format string. Lower case too.
do("AM/PM", "3PM==3pm==15h", "11AM==11am==11h")
// When parsing, if the seconds value is followed by a decimal point
// and some digits, that is taken as a fraction of a second even if
// the layout string does not represent the fractional second.
// Here we add a fractional second to our time value used above.
t, err = time.Parse(time.UnixDate, "Wed Feb 25 11:06:39.1234 PST 2015")
if err != nil {
panic(err)
}
// It does not appear in the output if the layout string does not contain
// a representation of the fractional second.
do("No fraction", time.UnixDate, "Wed Feb 25 11:06:39 PST 2015")
// Fractional seconds can be printed by adding a run of 0s or 9s after
// a decimal point in the seconds value in the layout string.
// If the layout digits are 0s, the fractional second is of the specified
// width. Note that the output has a trailing zero.
do("0s for fraction", "15:04:05.00000", "11:06:39.12340")
// If the fraction in the layout is 9s, trailing zeros are dropped.
do("9s for fraction", "15:04:05.99999999", "11:06:39.1234")
}
package main
import (
"fmt"
"time"
)
func main() {
// Parse a time value from a string in the standard Unix format.
t, err := time.Parse(time.UnixDate, "Sat Mar 7 11:06:39 PST 2015")
if err != nil { // Always check errors even if they should not happen.
panic(err)
}
// Define a helper function to make the examples' output look nice.
do := func(name, layout, want string) {
got := t.Format(layout)
if want != got {
fmt.Printf("error: for %q got %q; expected %q\n", layout, got, want)
return
}
fmt.Printf("%-16s %q gives %q\n", name, layout, got)
}
// The predefined constant Unix uses an underscore to pad the day.
do("Unix", time.UnixDate, "Sat Mar 7 11:06:39 PST 2015")
// For fixed-width printing of values, such as the date, that may be one or
// two characters (7 vs. 07), use an _ instead of a space in the layout string.
// Here we print just the day, which is 2 in our layout string and 7 in our
// value.
do("No pad", "<2>", "<7>")
// An underscore represents a space pad, if the date only has one digit.
do("Spaces", "<_2>", "< 7>")
// A "0" indicates zero padding for single-digit values.
do("Zeros", "<02>", "<07>")
// If the value is already the right width, padding is not used.
// For instance, the second (05 in the reference time) in our value is 39,
// so it doesn't need padding, but the minutes (04, 06) does.
do("Suppressed pad", "04:05", "06:39")
}
package main
import (
"fmt"
"time"
)
func main() {
t := time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC)
fmt.Println(t.GoString())
t = t.Add(1 * time.Minute)
fmt.Println(t.GoString())
t = t.AddDate(0, 1, 0)
fmt.Println(t.GoString())
t, _ = time.Parse("Jan 2, 2006 at 3:04pm (MST)", "Feb 3, 2013 at 7:54pm (UTC)")
fmt.Println(t.GoString())
}
package main
import (
"fmt"
"time"
)
func main() {
t := time.Date(0, 0, 0, 12, 15, 30, 918273645, time.UTC)
round := []time.Duration{
time.Nanosecond,
time.Microsecond,
time.Millisecond,
time.Second,
2 * time.Second,
time.Minute,
10 * time.Minute,
time.Hour,
}
for _, d := range round {
fmt.Printf("t.Round(%6s) = %s\n", d, t.Round(d).Format("15:04:05.999999999"))
}
}
package main
import (
"fmt"
"time"
)
func main() {
timeWithNanoseconds := time.Date(2000, 2, 1, 12, 13, 14, 15, time.UTC)
withNanoseconds := timeWithNanoseconds.String()
timeWithoutNanoseconds := time.Date(2000, 2, 1, 12, 13, 14, 0, time.UTC)
withoutNanoseconds := timeWithoutNanoseconds.String()
fmt.Printf("withNanoseconds = %v\n", string(withNanoseconds))
fmt.Printf("withoutNanoseconds = %v\n", string(withoutNanoseconds))
}
package main
import (
"fmt"
"time"
)
func main() {
start := time.Date(2000, 1, 1, 0, 0, 0, 0, time.UTC)
end := time.Date(2000, 1, 1, 12, 0, 0, 0, time.UTC)
difference := end.Sub(start)
fmt.Printf("difference = %v\n", difference)
}
package main
import (
"fmt"
"time"
)
func main() {
t, _ := time.Parse("2006 Jan 02 15:04:05", "2012 Dec 07 12:15:30.918273645")
trunc := []time.Duration{
time.Nanosecond,
time.Microsecond,
time.Millisecond,
time.Second,
2 * time.Second,
time.Minute,
10 * time.Minute,
}
for _, d := range trunc {
fmt.Printf("t.Truncate(%5s) = %s\n", d, t.Truncate(d).Format("15:04:05.999999999"))
}
// To round to the last midnight in the local timezone, create a new Date.
midnight := time.Date(t.Year(), t.Month(), t.Day(), 0, 0, 0, 0, time.Local)
_ = midnight
}
package main
import (
"fmt"
"time"
)
func main() {
// 1 billion seconds of Unix, three ways.
fmt.Println(time.Unix(1e9, 0).UTC()) // 1e9 seconds
fmt.Println(time.Unix(0, 1e18).UTC()) // 1e18 nanoseconds
fmt.Println(time.Unix(2e9, -1e18).UTC()) // 2e9 seconds - 1e18 nanoseconds
t := time.Date(2001, time.September, 9, 1, 46, 40, 0, time.UTC)
fmt.Println(t.Unix()) // seconds since 1970
fmt.Println(t.UnixNano()) // nanoseconds since 1970
}
package main
import (
"fmt"
"time"
)
func main() {
unixTime := time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC)
fmt.Println(unixTime.Unix())
t := time.Unix(unixTime.Unix(), 0).UTC()
fmt.Println(t)
}
package main
import (
"fmt"
"time"
)
func main() {
umt := time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC)
fmt.Println(umt.UnixMicro())
t := time.UnixMicro(umt.UnixMicro()).UTC()
fmt.Println(t)
}
package main
import (
"fmt"
"time"
)
func main() {
umt := time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC)
fmt.Println(umt.UnixMilli())
t := time.UnixMilli(umt.UnixMilli()).UTC()
fmt.Println(t)
}
package main
import (
"fmt"
"math"
"time"
)
func main() {
futureTime := time.Now().Add(5 * time.Second)
durationUntil := time.Until(futureTime)
fmt.Printf("Duration until future time: %.0f seconds", math.Ceil(durationUntil.Seconds()))
}
A Location maps time instants to the zone in use at that time.
Typically, the Location represents the collection of time offsets
in use in a geographical area. For many Locations the time offset varies
depending on whether daylight savings time is in use at the time instant.
Location is used to provide a time zone in a printed Time value and for
calculations involving intervals that may cross daylight savings time
boundaries. String returns a descriptive name for the time zone information,
corresponding to the name argument to [LoadLocation] or [FixedZone].
*Location : expvar.Var
*Location : fmt.Stringer
func FixedZone(name string, offset int) *Location
func LoadLocation(name string) (*Location, error)
func LoadLocationFromTZData(name string, data []byte) (*Location, error)
func Time.Location() *Location
func Date(year int, month Month, day, hour, min, sec, nsec int, loc *Location) Time
func ParseInLocation(layout, value string, loc *Location) (Time, error)
func Time.In(loc *Location) Time
var Local *Location
var UTC *Location
A Ticker holds a channel that delivers “ticks” of a clock
at intervals. // The channel on which the ticks are delivered. Reset stops a ticker and resets its period to the specified duration.
The next tick will arrive after the new period elapses. The duration d
must be greater than zero; if not, Reset will panic. Stop turns off a ticker. After Stop, no more ticks will be sent.
Stop does not close the channel, to prevent a concurrent goroutine
reading from the channel from seeing an erroneous "tick".
func NewTicker(d Duration) *Ticker
A Time represents an instant in time with nanosecond precision.
Programs using times should typically store and pass them as values,
not pointers. That is, time variables and struct fields should be of
type [time.Time], not *time.Time.
A Time value can be used by multiple goroutines simultaneously except
that the methods [Time.GobDecode], [Time.UnmarshalBinary], [Time.UnmarshalJSON] and
[Time.UnmarshalText] are not concurrency-safe.
Time instants can be compared using the [Time.Before], [Time.After], and [Time.Equal] methods.
The [Time.Sub] method subtracts two instants, producing a [Duration].
The [Time.Add] method adds a Time and a Duration, producing a Time.
The zero value of type Time is January 1, year 1, 00:00:00.000000000 UTC.
As this time is unlikely to come up in practice, the [Time.IsZero] method gives
a simple way of detecting a time that has not been initialized explicitly.
Each time has an associated [Location]. The methods [Time.Local], [Time.UTC], and Time.In return a
Time with a specific Location. Changing the Location of a Time value with
these methods does not change the actual instant it represents, only the time
zone in which to interpret it.
Representations of a Time value saved by the [Time.GobEncode], [Time.MarshalBinary], [Time.AppendBinary],
[Time.MarshalJSON], [Time.MarshalText] and [Time.AppendText] methods store the [Time.Location]'s offset,
but not the location name. They therefore lose information about Daylight Saving Time.
In addition to the required “wall clock” reading, a Time may contain an optional
reading of the current process's monotonic clock, to provide additional precision
for comparison or subtraction.
See the “Monotonic Clocks” section in the package documentation for details.
Note that the Go == operator compares not just the time instant but also the
Location and the monotonic clock reading. Therefore, Time values should not
be used as map or database keys without first guaranteeing that the
identical Location has been set for all values, which can be achieved
through use of the UTC or Local method, and that the monotonic clock reading
has been stripped by setting t = t.Round(0). In general, prefer t.Equal(u)
to t == u, since t.Equal uses the most accurate comparison available and
correctly handles the case when only one of its arguments has a monotonic
clock reading. Add returns the time t+d. AddDate returns the time corresponding to adding the
given number of years, months, and days to t.
For example, AddDate(-1, 2, 3) applied to January 1, 2011
returns March 4, 2010.
Note that dates are fundamentally coupled to timezones, and calendrical
periods like days don't have fixed durations. AddDate uses the Location of
the Time value to determine these durations. That means that the same
AddDate arguments can produce a different shift in absolute time depending on
the base Time value and its Location. For example, AddDate(0, 0, 1) applied
to 12:00 on March 27 always returns 12:00 on March 28. At some locations and
in some years this is a 24 hour shift. In others it's a 23 hour shift due to
daylight savings time transitions.
AddDate normalizes its result in the same way that Date does,
so, for example, adding one month to October 31 yields
December 1, the normalized form for November 31. After reports whether the time instant t is after u. AppendBinary implements the [encoding.BinaryAppender] interface. AppendFormat is like [Time.Format] but appends the textual
representation to b and returns the extended buffer. AppendText implements the [encoding.TextAppender] interface.
The time is formatted in RFC 3339 format with sub-second precision.
If the timestamp cannot be represented as valid RFC 3339
(e.g., the year is out of range), then an error is returned. Before reports whether the time instant t is before u. Clock returns the hour, minute, and second within the day specified by t. Compare compares the time instant t with u. If t is before u, it returns -1;
if t is after u, it returns +1; if they're the same, it returns 0. Date returns the year, month, and day in which t occurs. Day returns the day of the month specified by t. Equal reports whether t and u represent the same time instant.
Two times can be equal even if they are in different locations.
For example, 6:00 +0200 and 4:00 UTC are Equal.
See the documentation on the Time type for the pitfalls of using == with
Time values; most code should use Equal instead. Format returns a textual representation of the time value formatted according
to the layout defined by the argument. See the documentation for the
constant called [Layout] to see how to represent the layout format.
The executable example for [Time.Format] demonstrates the working
of the layout string in detail and is a good reference. GoString implements [fmt.GoStringer] and formats t to be printed in Go source
code. GobDecode implements the gob.GobDecoder interface. GobEncode implements the gob.GobEncoder interface. Hour returns the hour within the day specified by t, in the range [0, 23]. ISOWeek returns the ISO 8601 year and week number in which t occurs.
Week ranges from 1 to 53. Jan 01 to Jan 03 of year n might belong to
week 52 or 53 of year n-1, and Dec 29 to Dec 31 might belong to week 1
of year n+1. In returns a copy of t representing the same time instant, but
with the copy's location information set to loc for display
purposes.
In panics if loc is nil. IsDST reports whether the time in the configured location is in Daylight Savings Time. IsZero reports whether t represents the zero time instant,
January 1, year 1, 00:00:00 UTC. Local returns t with the location set to local time. Location returns the time zone information associated with t. MarshalBinary implements the [encoding.BinaryMarshaler] interface. MarshalJSON implements the [encoding/json.Marshaler] interface.
The time is a quoted string in the RFC 3339 format with sub-second precision.
If the timestamp cannot be represented as valid RFC 3339
(e.g., the year is out of range), then an error is reported. MarshalText implements the [encoding.TextMarshaler] interface. The output
matches that of calling the [Time.AppendText] method.
See [Time.AppendText] for more information. Minute returns the minute offset within the hour specified by t, in the range [0, 59]. Month returns the month of the year specified by t. Nanosecond returns the nanosecond offset within the second specified by t,
in the range [0, 999999999]. Round returns the result of rounding t to the nearest multiple of d (since the zero time).
The rounding behavior for halfway values is to round up.
If d <= 0, Round returns t stripped of any monotonic clock reading but otherwise unchanged.
Round operates on the time as an absolute duration since the
zero time; it does not operate on the presentation form of the
time. Thus, Round(Hour) may return a time with a non-zero
minute, depending on the time's Location. Second returns the second offset within the minute specified by t, in the range [0, 59]. String returns the time formatted using the format string
"2006-01-02 15:04:05.999999999 -0700 MST"
If the time has a monotonic clock reading, the returned string
includes a final field "m=±<value>", where value is the monotonic
clock reading formatted as a decimal number of seconds.
The returned string is meant for debugging; for a stable serialized
representation, use t.MarshalText, t.MarshalBinary, or t.Format
with an explicit format string. Sub returns the duration t-u. If the result exceeds the maximum (or minimum)
value that can be stored in a [Duration], the maximum (or minimum) duration
will be returned.
To compute t-d for a duration d, use t.Add(-d). Truncate returns the result of rounding t down to a multiple of d (since the zero time).
If d <= 0, Truncate returns t stripped of any monotonic clock reading but otherwise unchanged.
Truncate operates on the time as an absolute duration since the
zero time; it does not operate on the presentation form of the
time. Thus, Truncate(Hour) may return a time with a non-zero
minute, depending on the time's Location. UTC returns t with the location set to UTC. Unix returns t as a Unix time, the number of seconds elapsed
since January 1, 1970 UTC. The result does not depend on the
location associated with t.
Unix-like operating systems often record time as a 32-bit
count of seconds, but since the method here returns a 64-bit
value it is valid for billions of years into the past or future. UnixMicro returns t as a Unix time, the number of microseconds elapsed since
January 1, 1970 UTC. The result is undefined if the Unix time in
microseconds cannot be represented by an int64 (a date before year -290307 or
after year 294246). The result does not depend on the location associated
with t. UnixMilli returns t as a Unix time, the number of milliseconds elapsed since
January 1, 1970 UTC. The result is undefined if the Unix time in
milliseconds cannot be represented by an int64 (a date more than 292 million
years before or after 1970). The result does not depend on the
location associated with t. UnixNano returns t as a Unix time, the number of nanoseconds elapsed
since January 1, 1970 UTC. The result is undefined if the Unix time
in nanoseconds cannot be represented by an int64 (a date before the year
1678 or after 2262). Note that this means the result of calling UnixNano
on the zero Time is undefined. The result does not depend on the
location associated with t. UnmarshalBinary implements the [encoding.BinaryUnmarshaler] interface. UnmarshalJSON implements the [encoding/json.Unmarshaler] interface.
The time must be a quoted string in the RFC 3339 format. UnmarshalText implements the [encoding.TextUnmarshaler] interface.
The time must be in the RFC 3339 format. Weekday returns the day of the week specified by t. Year returns the year in which t occurs. YearDay returns the day of the year specified by t, in the range [1,365] for non-leap years,
and [1,366] in leap years. Zone computes the time zone in effect at time t, returning the abbreviated
name of the zone (such as "CET") and its offset in seconds east of UTC. ZoneBounds returns the bounds of the time zone in effect at time t.
The zone begins at start and the next zone begins at end.
If the zone begins at the beginning of time, start will be returned as a zero Time.
If the zone goes on forever, end will be returned as a zero Time.
The Location of the returned times will be the same as t.
Time : encoding.BinaryAppender
Time : encoding.BinaryMarshaler
*Time : encoding.BinaryUnmarshaler
Time : encoding.TextAppender
Time : encoding.TextMarshaler
*Time : encoding.TextUnmarshaler
*Time : encoding/gob.GobDecoder
Time : encoding/gob.GobEncoder
Time : encoding/json.Marshaler
*Time : encoding/json.Unmarshaler
Time : expvar.Var
Time : fmt.GoStringer
Time : fmt.Stringer
func After(d Duration) <-chan Time
func Date(year int, month Month, day, hour, min, sec, nsec int, loc *Location) Time
func Now() Time
func Parse(layout, value string) (Time, error)
func ParseInLocation(layout, value string, loc *Location) (Time, error)
func Tick(d Duration) <-chan Time
func Unix(sec int64, nsec int64) Time
func UnixMicro(usec int64) Time
func UnixMilli(msec int64) Time
func Time.Add(d Duration) Time
func Time.AddDate(years int, months int, days int) Time
func Time.In(loc *Location) Time
func Time.Local() Time
func Time.Round(d Duration) Time
func Time.Truncate(d Duration) Time
func Time.UTC() Time
func Time.ZoneBounds() (start, end Time)
func archive/tar.FileInfoNames.ModTime() Time
func archive/zip.(*FileHeader).ModTime() Time
func context.Context.Deadline() (deadline Time, ok bool)
func io/fs.FileInfo.ModTime() Time
func log/slog.Value.Time() Time
func net/http.ParseTime(text string) (t Time, err error)
func net/mail.ParseDate(date string) (Time, error)
func net/mail.Header.Date() (Time, error)
func os.FileInfo.ModTime() Time
func testing.(*T).Deadline() (deadline Time, ok bool)
func Since(t Time) Duration
func Until(t Time) Duration
func Time.After(u Time) bool
func Time.Before(u Time) bool
func Time.Compare(u Time) int
func Time.Equal(u Time) bool
func Time.Sub(u Time) Duration
func archive/zip.(*FileHeader).SetModTime(t Time)
func context.WithDeadline(parent context.Context, d Time) (context.Context, context.CancelFunc)
func context.WithDeadlineCause(parent context.Context, d Time, cause error) (context.Context, context.CancelFunc)
func crypto/tls.(*Conn).SetDeadline(t Time) error
func crypto/tls.(*Conn).SetReadDeadline(t Time) error
func crypto/tls.(*Conn).SetWriteDeadline(t Time) error
func crypto/x509.(*Certificate).CreateCRL(rand io.Reader, priv any, revokedCerts []pkix.RevokedCertificate, now, expiry Time) (crlBytes []byte, err error)
func crypto/x509/pkix.(*CertificateList).HasExpired(now Time) bool
func internal/poll.(*FD).SetDeadline(t Time) error
func internal/poll.(*FD).SetReadDeadline(t Time) error
func internal/poll.(*FD).SetWriteDeadline(t Time) error
func log/slog.NewRecord(t Time, level slog.Level, msg string, pc uintptr) slog.Record
func log/slog.Time(key string, v Time) slog.Attr
func log/slog.TimeValue(v Time) slog.Value
func net.Conn.SetDeadline(t Time) error
func net.Conn.SetReadDeadline(t Time) error
func net.Conn.SetWriteDeadline(t Time) error
func net.PacketConn.SetDeadline(t Time) error
func net.PacketConn.SetReadDeadline(t Time) error
func net.PacketConn.SetWriteDeadline(t Time) error
func net.(*TCPListener).SetDeadline(t Time) error
func net.(*UnixListener).SetDeadline(t Time) error
func net/http.ServeContent(w http.ResponseWriter, req *http.Request, name string, modtime Time, content io.ReadSeeker)
func net/http.(*ResponseController).SetReadDeadline(deadline Time) error
func net/http.(*ResponseController).SetWriteDeadline(deadline Time) error
func os.Chtimes(name string, atime Time, mtime Time) error
func os.Chtimes(name string, atime Time, mtime Time) error
func os.(*File).SetDeadline(t Time) error
func os.(*File).SetReadDeadline(t Time) error
func os.(*File).SetWriteDeadline(t Time) error
func vendor/golang.org/x/crypto/cryptobyte.(*Builder).AddASN1GeneralizedTime(t Time)
func vendor/golang.org/x/crypto/cryptobyte.(*Builder).AddASN1UTCTime(t Time)
func vendor/golang.org/x/crypto/cryptobyte.(*String).ReadASN1GeneralizedTime(out *Time) bool
func vendor/golang.org/x/crypto/cryptobyte.(*String).ReadASN1UTCTime(out *Time) bool
The Timer type represents a single event.
When the Timer expires, the current time will be sent on C,
unless the Timer was created by [AfterFunc].
A Timer must be created with [NewTimer] or AfterFunc.C<-chan Time Reset changes the timer to expire after duration d.
It returns true if the timer had been active, false if the timer had
expired or been stopped.
For a func-based timer created with [AfterFunc](d, f), Reset either reschedules
when f will run, in which case Reset returns true, or schedules f
to run again, in which case it returns false.
When Reset returns false, Reset neither waits for the prior f to
complete before returning nor does it guarantee that the subsequent
goroutine running f does not run concurrently with the prior
one. If the caller needs to know whether the prior execution of
f is completed, it must coordinate with f explicitly.
For a chan-based timer created with NewTimer, as of Go 1.23,
any receive from t.C after Reset has returned is guaranteed not
to receive a time value corresponding to the previous timer settings;
if the program has not received from t.C already and the timer is
running, Reset is guaranteed to return true.
Before Go 1.23, the only safe way to use Reset was to call [Timer.Stop]
and explicitly drain the timer first.
See the [NewTimer] documentation for more details. Stop prevents the [Timer] from firing.
It returns true if the call stops the timer, false if the timer has already
expired or been stopped.
For a func-based timer created with [AfterFunc](d, f),
if t.Stop returns false, then the timer has already expired
and the function f has been started in its own goroutine;
Stop does not wait for f to complete before returning.
If the caller needs to know whether f is completed,
it must coordinate with f explicitly.
For a chan-based timer created with NewTimer(d), as of Go 1.23,
any receive from t.C after Stop has returned is guaranteed to block
rather than receive a stale time value from before the Stop;
if the program has not received from t.C already and the timer is
running, Stop is guaranteed to return true.
Before Go 1.23, the only safe way to use Stop was insert an extra
<-t.C if Stop returned false to drain a potential stale value.
See the [NewTimer] documentation for more details.
func AfterFunc(d Duration, f func()) *Timer
func NewTimer(d Duration) *Timer
A Weekday specifies a day of the week (Sunday = 0, ...). String returns the English name of the day ("Sunday", "Monday", ...).
Weekday : expvar.Var
Weekday : fmt.Stringer
func Time.Weekday() Weekday
const Friday
const Monday
const Saturday
const Sunday
const Thursday
const Tuesday
const Wednesday
Package-Level Functions (total 19)
After waits for the duration to elapse and then sends the current time
on the returned channel.
It is equivalent to [NewTimer](d).C.
Before Go 1.23, this documentation warned that the underlying
[Timer] would not be recovered by the garbage collector until the
timer fired, and that if efficiency was a concern, code should use
NewTimer instead and call [Timer.Stop] if the timer is no longer needed.
As of Go 1.23, the garbage collector can recover unreferenced,
unstopped timers. There is no reason to prefer NewTimer when After will do.
AfterFunc waits for the duration to elapse and then calls f
in its own goroutine. It returns a [Timer] that can
be used to cancel the call using its Stop method.
The returned Timer's C field is not used and will be nil.
Date returns the Time corresponding to
yyyy-mm-dd hh:mm:ss + nsec nanoseconds
in the appropriate zone for that time in the given location.
The month, day, hour, min, sec, and nsec values may be outside
their usual ranges and will be normalized during the conversion.
For example, October 32 converts to November 1.
A daylight savings time transition skips or repeats times.
For example, in the United States, March 13, 2011 2:15am never occurred,
while November 6, 2011 1:15am occurred twice. In such cases, the
choice of time zone, and therefore the time, is not well-defined.
Date returns a time that is correct in one of the two zones involved
in the transition, but it does not guarantee which.
Date panics if loc is nil.
FixedZone returns a [Location] that always uses
the given zone name and offset (seconds east of UTC).
LoadLocation returns the Location with the given name.
If the name is "" or "UTC", LoadLocation returns UTC.
If the name is "Local", LoadLocation returns Local.
Otherwise, the name is taken to be a location name corresponding to a file
in the IANA Time Zone database, such as "America/New_York".
LoadLocation looks for the IANA Time Zone database in the following
locations in order:
- the directory or uncompressed zip file named by the ZONEINFO environment variable
- on a Unix system, the system standard installation location
- $GOROOT/lib/time/zoneinfo.zip
- the time/tzdata package, if it was imported
LoadLocationFromTZData returns a Location with the given name
initialized from the IANA Time Zone database-formatted data.
The data should be in the format of a standard IANA time zone file
(for example, the content of /etc/localtime on Unix systems).
NewTicker returns a new [Ticker] containing a channel that will send
the current time on the channel after each tick. The period of the
ticks is specified by the duration argument. The ticker will adjust
the time interval or drop ticks to make up for slow receivers.
The duration d must be greater than zero; if not, NewTicker will
panic.
Before Go 1.23, the garbage collector did not recover
tickers that had not yet expired or been stopped, so code often
immediately deferred t.Stop after calling NewTicker, to make
the ticker recoverable when it was no longer needed.
As of Go 1.23, the garbage collector can recover unreferenced
tickers, even if they haven't been stopped.
The Stop method is no longer necessary to help the garbage collector.
(Code may of course still want to call Stop to stop the ticker for other reasons.)
NewTimer creates a new Timer that will send
the current time on its channel after at least duration d.
Before Go 1.23, the garbage collector did not recover
timers that had not yet expired or been stopped, so code often
immediately deferred t.Stop after calling NewTimer, to make
the timer recoverable when it was no longer needed.
As of Go 1.23, the garbage collector can recover unreferenced
timers, even if they haven't expired or been stopped.
The Stop method is no longer necessary to help the garbage collector.
(Code may of course still want to call Stop to stop the timer for other reasons.)
Before Go 1.23, the channel associated with a Timer was
asynchronous (buffered, capacity 1), which meant that
stale time values could be received even after [Timer.Stop]
or [Timer.Reset] returned.
As of Go 1.23, the channel is synchronous (unbuffered, capacity 0),
eliminating the possibility of those stale values.
The GODEBUG setting asynctimerchan=1 restores both pre-Go 1.23
behaviors: when set, unexpired timers won't be garbage collected, and
channels will have buffered capacity. This setting may be removed
in Go 1.27 or later.
Now returns the current local time.
Parse parses a formatted string and returns the time value it represents.
See the documentation for the constant called [Layout] to see how to
represent the format. The second argument must be parseable using
the format string (layout) provided as the first argument.
The example for [Time.Format] demonstrates the working of the layout string
in detail and is a good reference.
When parsing (only), the input may contain a fractional second
field immediately after the seconds field, even if the layout does not
signify its presence. In that case either a comma or a decimal point
followed by a maximal series of digits is parsed as a fractional second.
Fractional seconds are truncated to nanosecond precision.
Elements omitted from the layout are assumed to be zero or, when
zero is impossible, one, so parsing "3:04pm" returns the time
corresponding to Jan 1, year 0, 15:04:00 UTC (note that because the year is
0, this time is before the zero Time).
Years must be in the range 0000..9999. The day of the week is checked
for syntax but it is otherwise ignored.
For layouts specifying the two-digit year 06, a value NN >= 69 will be treated
as 19NN and a value NN < 69 will be treated as 20NN.
The remainder of this comment describes the handling of time zones.
In the absence of a time zone indicator, Parse returns a time in UTC.
When parsing a time with a zone offset like -0700, if the offset corresponds
to a time zone used by the current location ([Local]), then Parse uses that
location and zone in the returned time. Otherwise it records the time as
being in a fabricated location with time fixed at the given zone offset.
When parsing a time with a zone abbreviation like MST, if the zone abbreviation
has a defined offset in the current location, then that offset is used.
The zone abbreviation "UTC" is recognized as UTC regardless of location.
If the zone abbreviation is unknown, Parse records the time as being
in a fabricated location with the given zone abbreviation and a zero offset.
This choice means that such a time can be parsed and reformatted with the
same layout losslessly, but the exact instant used in the representation will
differ by the actual zone offset. To avoid such problems, prefer time layouts
that use a numeric zone offset, or use [ParseInLocation].
ParseDuration parses a duration string.
A duration string is a possibly signed sequence of
decimal numbers, each with optional fraction and a unit suffix,
such as "300ms", "-1.5h" or "2h45m".
Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h".
ParseInLocation is like Parse but differs in two important ways.
First, in the absence of time zone information, Parse interprets a time as UTC;
ParseInLocation interprets the time as in the given location.
Second, when given a zone offset or abbreviation, Parse tries to match it
against the Local location; ParseInLocation uses the given location.
Since returns the time elapsed since t.
It is shorthand for time.Now().Sub(t).
Sleep pauses the current goroutine for at least the duration d.
A negative or zero duration causes Sleep to return immediately.
Tick is a convenience wrapper for [NewTicker] providing access to the ticking
channel only. Unlike NewTicker, Tick will return nil if d <= 0.
Before Go 1.23, this documentation warned that the underlying
[Ticker] would never be recovered by the garbage collector, and that
if efficiency was a concern, code should use NewTicker instead and
call [Ticker.Stop] when the ticker is no longer needed.
As of Go 1.23, the garbage collector can recover unreferenced
tickers, even if they haven't been stopped.
The Stop method is no longer necessary to help the garbage collector.
There is no longer any reason to prefer NewTicker when Tick will do.
Unix returns the local Time corresponding to the given Unix time,
sec seconds and nsec nanoseconds since January 1, 1970 UTC.
It is valid to pass nsec outside the range [0, 999999999].
Not all sec values have a corresponding time value. One such
value is 1<<63-1 (the largest int64 value).
UnixMicro returns the local Time corresponding to the given Unix time,
usec microseconds since January 1, 1970 UTC.
UnixMilli returns the local Time corresponding to the given Unix time,
msec milliseconds since January 1, 1970 UTC.
Until returns the duration until t.
It is shorthand for t.Sub(time.Now()).
Package-Level Variables (total 2)
Local represents the system's local time zone.
On Unix systems, Local consults the TZ environment
variable to find the time zone to use. No TZ means
use the system default /etc/localtime.
TZ="" means use UTC.
TZ="foo" means use file foo in the system timezone directory.
UTC represents Universal Coordinated Time (UTC).
Package-Level Constants (total 44)
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
Common durations. There is no definition for units of Day or larger
to avoid confusion across daylight savings time zone transitions.
To count the number of units in a [Duration], divide:
second := time.Second
fmt.Print(int64(second/time.Millisecond)) // prints 1000
To convert an integer number of units to a Duration, multiply:
seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
Common durations. There is no definition for units of Day or larger
to avoid confusion across daylight savings time zone transitions.
To count the number of units in a [Duration], divide:
second := time.Second
fmt.Print(int64(second/time.Millisecond)) // prints 1000
To convert an integer number of units to a Duration, multiply:
seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s
Common durations. There is no definition for units of Day or larger
to avoid confusion across daylight savings time zone transitions.
To count the number of units in a [Duration], divide:
second := time.Second
fmt.Print(int64(second/time.Millisecond)) // prints 1000
To convert an integer number of units to a Duration, multiply:
seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s
Common durations. There is no definition for units of Day or larger
to avoid confusion across daylight savings time zone transitions.
To count the number of units in a [Duration], divide:
second := time.Second
fmt.Print(int64(second/time.Millisecond)) // prints 1000
To convert an integer number of units to a Duration, multiply:
seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s
Common durations. There is no definition for units of Day or larger
to avoid confusion across daylight savings time zone transitions.
To count the number of units in a [Duration], divide:
second := time.Second
fmt.Print(int64(second/time.Millisecond)) // prints 1000
To convert an integer number of units to a Duration, multiply:
seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
Common durations. There is no definition for units of Day or larger
to avoid confusion across daylight savings time zone transitions.
To count the number of units in a [Duration], divide:
second := time.Second
fmt.Print(int64(second/time.Millisecond)) // prints 1000
To convert an integer number of units to a Duration, multiply:
seconds := 10
fmt.Print(time.Duration(seconds)*time.Second) // prints 10s
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
These are predefined layouts for use in [Time.Format] and [time.Parse].
The reference time used in these layouts is the specific time stamp:
01/02 03:04:05PM '06 -0700
(January 2, 15:04:05, 2006, in time zone seven hours west of GMT).
That value is recorded as the constant named [Layout], listed below. As a Unix
time, this is 1136239445. Since MST is GMT-0700, the reference would be
printed by the Unix date command as:
Mon Jan 2 15:04:05 MST 2006
It is a regrettable historic error that the date uses the American convention
of putting the numerical month before the day.
The example for Time.Format demonstrates the working of the layout string
in detail and is a good reference.
Note that the [RFC822], [RFC850], and [RFC1123] formats should be applied
only to local times. Applying them to UTC times will use "UTC" as the
time zone abbreviation, while strictly speaking those RFCs require the
use of "GMT" in that case.
When using the [RFC1123] or [RFC1123Z] formats for parsing, note that these
formats define a leading zero for the day-in-month portion, which is not
strictly allowed by RFC 1123. This will result in an error when parsing
date strings that occur in the first 9 days of a given month.
In general [RFC1123Z] should be used instead of [RFC1123] for servers
that insist on that format, and [RFC3339] should be preferred for new protocols.
[RFC3339], [RFC822], [RFC822Z], [RFC1123], and [RFC1123Z] are useful for formatting;
when used with time.Parse they do not accept all the time formats
permitted by the RFCs and they do accept time formats not formally defined.
The [RFC3339Nano] format removes trailing zeros from the seconds field
and thus may not sort correctly once formatted.
Most programs can use one of the defined constants as the layout passed to
Format or Parse. The rest of this comment can be ignored unless you are
creating a custom layout string.
To define your own format, write down what the reference time would look like
formatted your way; see the values of constants like [ANSIC], [StampMicro] or
[Kitchen] for examples. The model is to demonstrate what the reference time
looks like so that the Format and Parse methods can apply the same
transformation to a general time value.
Here is a summary of the components of a layout string. Each element shows by
example the formatting of an element of the reference time. Only these values
are recognized. Text in the layout string that is not recognized as part of
the reference time is echoed verbatim during Format and expected to appear
verbatim in the input to Parse.
Year: "2006" "06"
Month: "Jan" "January" "01" "1"
Day of the week: "Mon" "Monday"
Day of the month: "2" "_2" "02"
Day of the year: "__2" "002"
Hour: "15" "3" "03" (PM or AM)
Minute: "4" "04"
Second: "5" "05"
AM/PM mark: "PM"
Numeric time zone offsets format as follows:
"-0700" ±hhmm
"-07:00" ±hh:mm
"-07" ±hh
"-070000" ±hhmmss
"-07:00:00" ±hh:mm:ss
Replacing the sign in the format with a Z triggers
the ISO 8601 behavior of printing Z instead of an
offset for the UTC zone. Thus:
"Z0700" Z or ±hhmm
"Z07:00" Z or ±hh:mm
"Z07" Z or ±hh
"Z070000" Z or ±hhmmss
"Z07:00:00" Z or ±hh:mm:ss
Within the format string, the underscores in "_2" and "__2" represent spaces
that may be replaced by digits if the following number has multiple digits,
for compatibility with fixed-width Unix time formats. A leading zero represents
a zero-padded value.
The formats __2 and 002 are space-padded and zero-padded
three-character day of year; there is no unpadded day of year format.
A comma or decimal point followed by one or more zeros represents
a fractional second, printed to the given number of decimal places.
A comma or decimal point followed by one or more nines represents
a fractional second, printed to the given number of decimal places, with
trailing zeros removed.
For example "15:04:05,000" or "15:04:05.000" formats or parses with
millisecond precision.
Some valid layouts are invalid time values for time.Parse, due to formats
such as _ for space padding and Z for zone information.
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