JavaScript date comparisons

Question

I am new to the lower level useful functions of JavaScript, and I find myself needing to compare two date objects, but within an hourly range. For example, if Date1 is less then two hours until (or from) Date2. How could this be done?

Answer 1

The Date.UTC() method returns the number of milliseconds in a date string since midnight of January 1, 1970, according to universal time. Get both UTC values for the dates and then subtract them. For no more than a hour difference the result should be less than 3600000(1000*60*60).

Answer 2

You can perform mathematical operations on Date objects, they will get converted to integers. Substracting two date objects will give you the difference in milliseconds. Two hours = 120 minutes = 7200 seconds = 7200000 milliseconds.

var d1 = new Date('5/13/2010 08:30');
var d2 = new Date('5/13/2010 10:00');

if( d2 - d1  < 7200000 ){
//less than two hours difference
}