Time

Go offers extensive support for times and durations; here are some examples.

package main

import (
    "fmt"
    "time"
)

func main() {
    p := fmt.Println

    // We’ll start by getting the current time.
    now := time.Now()
    p(now)

    // You can build a time struct by providing the year, month, day, etc.
    // Times are always associated with a Location, i.e. time zone.
    then := time.Date(
        2009, 11, 17, 20, 34, 58, 651387237, time.UTC)
    p(then)

    // You can extract the various components of the time value as expected.
    p(then.Year())
    p(then.Month())
    p(then.Day())
    p(then.Hour())
    p(then.Minute())
    p(then.Second())
    p(then.Nanosecond())
    p(then.Location())

    // The Monday-Sunday Weekday is also available.
    p(then.Weekday())

    // These methods compare two times, testing if the first 
    // occurs before, after, or at the same time as the second, respectively.
    p(then.Before(now))
    p(then.After(now))
    p(then.Equal(now))

    // The Sub methods returns a Duration representing the interval between two times.
    diff := now.Sub(then)
    p(diff)

    // We can compute the length of the duration in various units.
    p(diff.Hours())
    p(diff.Minutes())
    p(diff.Seconds())
    p(diff.Nanoseconds())

    // You can use Add to advance a time by a given duration
    // or with a - to move backwards by a duration.
    p(then.Add(diff))
    p(then.Add(-diff))
}

$ go run time.go
2012-10-31 15:50:13.793654 +0000 UTC
2009-11-17 20:34:58.651387237 +0000 UTC
2009
November
17
20
34
58
651387237
UTC
Tuesday
true
false
false
25891h15m15.142266763s
25891.25420618521
1.5534752523711128e+06
9.320851514226677e+07
93208515142266763
2012-10-31 15:50:13.793654 +0000 UTC
2006-12-05 01:19:43.509120474 +0000 UTC

Next we’ll look at the related idea of time relative to the Unix epoch.