GeezerVison

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.