Difference between two time.Time objects

Question

Very new to the 'Go'. Question might be basic one.

I have two time.Time objects and I want to get the difference between the two in terms of hours/minutes/seconds. Lets say:

t1 = 2016-09-09 19:09:16 +0530 IST t2 = 2016-09-09 19:09:16 +0530 IST 

In above case, since the difference is 0. It should give me 00:00:00. Consider another case:

t1 = 2016-09-14 14:12:48 +0530 IST t2 = 2016-09-14 14:18:29 +0530 IST 

In this case, difference would be 00:05:41. I looked at the https://godoc.org/time but could not make anything out of it.

Answer 1

You may use Time.Sub() to get the difference between the 2 time.Time values, result will be a value of time.Duration.

When printed, a time.Duration formats itself "intelligently":

t1 := time.Now() t2 := t1.Add(time.Second * 341)  fmt.Println(t1) fmt.Println(t2)  diff := t2.Sub(t1) fmt.Println(diff) 

Output:

2009-11-10 23:00:00 +0000 UTC 2009-11-10 23:05:41 +0000 UTC 5m41s 

If you want the time format HH:mm:ss, you may constuct a time.Time value and use its Time.Format() method like this:

out := time.Time{}.Add(diff) fmt.Println(out.Format("15:04:05")) 

Output:

00:05:41 

Try the examples on the Go Playground.

Of course this will only work if the time difference is less than a day. If the difference may be bigger, then it's another story. The result must include days, months and years. Complexity increases significnatly. See this question for details:

golang time.Since() with months and years

The solution presented there solves this issue by showing a function with signature:

func diff(a, b time.Time) (year, month, day, hour, min, sec int) 

You may use that even if your times are within 24 hours (in which case year, month and day will be 0).