Does anyone know how to calculate the difference between two datetimes in Javascript ?

For example: 2018-01-17T21:18:00 and 2018-01-16T21:17:00

I tried to split them and add them together afterwards but I noticed the hours are already calculated in the date difference.

Why don´t people understand the simple difference between date and datetime ? Stop Voting down, or writing stuipid ments.

Does anyone know how to calculate the difference between two datetimes in Javascript ?

For example: 2018-01-17T21:18:00 and 2018-01-16T21:17:00

I tried to split them and add them together afterwards but I noticed the hours are already calculated in the date difference.

Why don´t people understand the simple difference between date and datetime ? Stop Voting down, or writing stuipid ments.

• javascript
• datetime

Share Improve this question Follow edited Jan 20, 2018 at 20:06 Deadpool asked Jan 20, 2018 at 18:58 DeadpoolDeadpool 20433 silver badges1414 bronze badges 5

• 1 Possible duplicate of Get difference between 2 dates in JavaScript? – Nikola Andreev Commented Jan 20, 2018 at 19:04
• 3 @NikolaAndreev Date and DateTime - BIG difference – Deadpool Commented Jan 20, 2018 at 19:05
• 1 @Deadpool in which form do you want the result? The as datetime? – Orkhan Alikhanov Commented Jan 20, 2018 at 19:12
• The best would be like 1 Day, 1 Hour and 1 Minute, but I can format it myself afterwards. :) – Deadpool Commented Jan 20, 2018 at 19:14
• If you use Moment.js library it has lot of functions to do that already see stackoverflow./questions/25150570/… – Aman B Commented Jan 20, 2018 at 19:22

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2 Answers 2

Sorted by: Reset to default 3

use Math.abs if you would get a negative value (ie if you don't know if a is lower then b)

Date object is essentially a number and you can do mathematical operations with it without getting timestamp

var a = new Date('2018-01-17T21:18:00')
var b = new Date('2018-01-16T21:17:00')

console.log(a - b) // possible use
console.log(Math.abs(a - b)) // safe to use
console.log(Math.abs(b - a)) // safe to use
console.log(b - a) // not what you want

from there you just calculate how many days/hours/min there is

you can use valueOf -> https://developer.mozilla/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/valueOf

let date1 = new Date('2018-01-17T21:18:00')
let date2 = new Date('2018-01-16T21:17:00')
//you get the difference in ms
let difference = Math.abs(date1.valueOf()-date2.valueOf())
//you can then convert to any format