Difference between two time.Time objects

datetime go time

105,602

Solution 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).

Solution 2

Actually, the time package's documentation does discuss it:

https://godoc.org/time#Time.Sub

https://godoc.org/time#Duration.Hours

You should produce a Duration object using Sub() and then use one of the Seconds(), Minutes(), Hours().

package main

import (
        "fmt"
        "time"
)

func main() {
        t1 := time.Date(1984, time.November, 3, 13, 0, 0, 0, time.UTC)
        t2 := time.Date(1984, time.November, 3, 10, 0, 0, 0, time.UTC)
        fmt.Printf("The hours difference is: %f", t1.Sub(t2).Hours())
}

Solution 3

To complement Shmulik Klein's answer:

Another way to calculate disjoint hours/minutes/seconds out of a time.Duration:

https://play.golang.org/p/VRoXG5NxLo

package main

import (
    "fmt"
    "math"
    "time"
)

func main() {
    t1 := time.Date(1984, time.November, 3, 13, 0, 0, 0, time.UTC)
    t2 := time.Date(1984, time.November, 3, 10, 23, 34, 0, time.UTC)

    hs := t1.Sub(t2).Hours()

    hs, mf := math.Modf(hs)
    ms := mf * 60

    ms, sf := math.Modf(ms)
    ss := sf * 60

    fmt.Println(hs, "hours", ms, "minutes", ss, "seconds")
}

2 hours 36 minutes 25.999999999999375 seconds

note:

slight precision loss due to the use of the float64 type
we ignore leap seconds and assume every minute has 60 seconds

105,602

Author by

Hemant Bhargava

Updated on December 17, 2021

Comments

Hemant Bhargava over 2 years
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.
Hemant Bhargava over 7 years

Okay, Thanks for the quick answer. I did it: var duration time.Duration = trip.EndTime.Sub(trip.StartTime) fmt.Println("Time difference: Minutes", duration.Minutes(), "Seconds: ", duration.Seconds()) But this does not seem to be giving the right numbers.
Shmulik Klein over 7 years

What is trip.EndTime\StartTime ?
Hemant Bhargava over 7 years

Sorry! Think of it as: t1 = trip.StartTime t2 = trip.EndTime
Shmulik Klein over 7 years

It is OK, but how does it implemented ?
Hemant Bhargava over 7 years

Implemented what? I did not write anything else than above two lines for the duration.
Hemant Bhargava over 7 years

Bang on! Thank you.
Hemant Bhargava over 7 years

How about if I say I need only hours or minutes?
Hemant Bhargava over 7 years

As I said, think of trip.Starttime and trip.EndTime as t1 and t2 respectively.
Hemant Bhargava over 7 years

Alright. Thanks for the edit. In your code, in case I need to get only hours/minutes, then?
Shmulik Klein over 7 years

Then just use fmt.Printf("The hours difference is: %d", t1.Sub(t2).Hours()) or fmt.Printf("The minutes difference is: %d", t1.Sub(t2).Minutes())
icza over 7 years

@HemantBhargava Then use a different layout string, one that only contains hours and minutes: out.Format("15:04")
Hemant Bhargava over 7 years

This is not working. t1 := time.Now() t2 := t1.Add(time.Second * 34100) diff := t2.Sub(t1) fmt.Println(diff.Minutes()) out := time.Time{}.Add(diff) fmt.Println(out.Format("15:30")) This outputs : 568.3333333333334 09:90 Which is not correct.
icza over 7 years

@HemantBhargava Yes of course because "15:30" is an invalid layout string. Please take the time and read the doc at Time.Format() to know what the layout string is. Using out.Format("15:04:05") outputs 09:28:20 which is correct. If you only need hour+min, then use out.Format("15:04") which outputs 09:28, as you can see this on the Go Playground.
jk-kim over 6 years

leap seconds considerations and data type consideration? this is a $1000 answer to $10 question...