How to get the hours difference between two date objects? [duplicate]

Question

The simplest way would be to directly subtract the date objects from one another.

For example:

var hours = Math.abs(date1 - date2) / 36e5;

The subtraction returns the difference between the two dates in milliseconds. 36e5 is the scientific notation for 60*60*1000, dividing by which converts the milliseconds difference into hours.

Try using getTime (mdn doc):

var diff = Math.abs(date1.getTime() - date2.getTime()) / 3600000;
if (diff < 18) { /* do something */ }

Using Math.abs() we don't know which date is the smallest. This code is probably more relevant:

var diff = (date1 - date2) / 3600000;
if (diff < 18) { array.push(date1); }

Use the timestamp you get by calling valueOf on the date object:

var diff = date2.valueOf() - date1.valueOf();
var diffInHours = diff/1000/60/60; // Convert milliseconds to hours