calculate number of hours between two times javascript code example

Example 1: javascript get hours difference between two dates

// date1 and date2 are date objects

let 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.

Example 2: javascript get seconds between two dates

var secondBetweenTwoDate = Math.abs((new Date().getTime() - oldDate.getTime()) / 1000);