How to calculate the number of months between two dates

actually i want to do that day calculation based on two different date. one date come from data base. another one is get from real device how can i do that?

kinda depends on how you want to determine a months

If you want to use built in.

Start is 2017-09-23T19:32:42.000Z
End is 2017-10-12T19:32:42.000Z

dateCompare(start: string,end: string) {

let startDt = new Date(start);
let endDt = new Date(end);

console.log(endDt.getMonth() - startDt.getMonth());  }

console ->
Date 2017-09-23T19:32:42.000Z date-functions.ts:25:4
Date 2017-10-12T19:32:42.000Z date-functions.ts:27:3
2017-8-6 date-functions.ts:30
2017-9-4 date-functions.ts:30:1
1 < this is just simple month numbers

or are you wanting to count days between
you can look here for examples

date functions