What's the best way to calculate date difference in Javascript

Question

I doing a function in Javascript like the VisualBasic DateDiff.

You give two dates and the returning time interval (Seconds, Minutes, Days, etc...)

DateDiff(ByVal Interval As Microsoft.VisualBasic.DateInterval, _
  ByVal Date1 As Date, ByVal Date2 As Date) as Long

So what's the best way to calculate the difference of Javascript Dates?

Answer 1

Use the Date object like so:

function DateDiff(var /*Date*/ date1, var /*Date*/ date2) {
    return date1.getTime() - date2.getTime();
}

This will return the number of milliseconds difference between the two dates. Converting it to seconds, minutes, hours etc. shouldn't be too difficult.