Validate two dates of this “dd-MMM-yyyy” format in javascript

Question

I have two dates 18-Aug-2010 and 19-Aug-2010 of this format. How to find whether which date is greater?

Answer 1

Firstly, the 'dd-MMM-yyyy' format isn't an accepted input format of the Date constructor (it returns an "invalid date" object) so we need to parse this ourselves. Let's write a function to return a Date object from a string in this format.

function parseMyDate(s) {
    var m = ['jan','feb','mar','apr','may','jun','jul','aug','sep','oct','nov','dec'];
    var match = s.match(/(\d+)-([^.]+)-(\d+)/);
    var date = match[1];
    var monthText = match[2];
    var year = match[3];
    var month = m.indexOf(monthText.toLowerCase());
    return new Date(year, month, date);
}

Date objects implicitly typecast to a number (milliseconds since 1970; epoch time) so you can compare using normal comparison operators:

if (parseMyDate(date1) > parseMyDate(date2)) ...