Number of hours between two strings in Javascript

Question

I have 2 strings "18:13:10" and "15:45:11" , I need to compute the number of hours between them ? For example a result of 6 hours and 17 minutes.

I'am working with reactjs.

Thanks

Duplicate of [Converting a time string to a time value in javascript](https://stackoverflow.com/q/46591254/215552) and [How to get the hours difference between two date objects?](https://stackoverflow.com/q/19225414/215552) — Heretic Monkey, Mar 20 '20 at 16:10
How is there "6 hours and 17 minutes" between 18:13:10 and 15:45:11? — Heretic Monkey, Mar 20 '20 at 16:32
Does this answer your question? [Javascript return number of days,hours,minutes,seconds between two dates](https://stackoverflow.com/questions/13903897/javascript-return-number-of-days-hours-minutes-seconds-between-two-dates) — Heretic Monkey, Mar 20 '20 at 16:34

terrymorse · Answer 1 · 2020-03-20T20:07:14.843

1

Let Date() do the heavy lifting for you:

    const d1 = new Date('1970-01-01T' + "18:13:10" + 'Z');
    const d2 = new Date('1970-01-01T' + '15:45:11' + 'Z');
    const diff = d1 - d2; // 887900

The time difference is in milliseconds. To get hours and minutes and seconds:

    const hours = Math.floor(diff/(1000*60*60)); // 2
    const mins = Math.floor((diff-(hours*1000*60*60)) / (1000*60)); // 27
    const secs = Math.floor(
      (diff-(hours*1000*60*60)-(mins*1000*60)) / 1000); // 59

edited Mar 20 '20 at 20:07

answered Mar 20 '20 at 16:01

terrymorse

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I tried to change 887900 ms to hours using this : https://www.timecalculator.net/milliseconds-to-hours and the result is 0.24 hours – xgeek652 Mar 20 '20 at 16:10
You need to have the next day in `d2`. – Heretic Monkey Mar 20 '20 at 16:11
@xgeek95 `const hours = Math.floor(ms/(1000*60*60))` and `const minutes = Math.floor(ms/(1000*60))` – HMR Mar 20 '20 at 16:12
@HereticMonkey Why use a different day for d2? The question does not specifiy a different day. – terrymorse Mar 20 '20 at 16:24
Well, the expected outcome, "6 hours and 17 minutes" does not appear to square with the difference between 15:45 and 18:13 if they are on the same day (that would be 2 hours and 27 minutes). But it doesn't square going the other way either, so who knows? – Heretic Monkey Mar 20 '20 at 16:29
@terrymorse how can I add number of seconds ? – xgeek652 Mar 20 '20 at 17:37
@xgeek95 - I'll add seconds to the answer above. – terrymorse Mar 20 '20 at 20:03

koalaok · Accepted Answer · 2020-03-20T16:39:44.900

0

Just create two instances of Date object prepending a date to the full time string. Use getTime and calculate the time difference. Then use getHours getMinutes and getSeconds methods on Date difference.

 const d1 = new Date('1970-01-01 ' + "18:13:10");
 const d2 = new Date('1970-01-01 ' + '10:01:01');

 var difference = d1.getTime() - d2.getTime();

 console.log(new Date(difference).getHours()-1 + ' ' + new Date(difference).getMinutes()+ ' ' + new Date(difference).getSeconds())

edited Mar 20 '20 at 16:39

answered Mar 20 '20 at 16:17

koalaok

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Questions which explain code are downvoted less often that just a dump of code, especially when that code uses different values than the OP. – Heretic Monkey Mar 20 '20 at 16:35
Oh really? Just edit my answer btw. Added some explanation to my dump of code. – koalaok Mar 20 '20 at 16:41

Number of hours between two strings in Javascript

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