Javascript: how to validate dates in format MM-DD-YYYY?

Question

I saw a potential answer here but that was for YYYY-MM-DD: http://paulschreiber.com/blog/2007/03/02/javascript-date-validation/

I modified the code code above for MM-DD-YYYY like so but I still can't get it to work:

String.prototype.isValidDate = function() 
{
     var IsoDateRe = new RegExp("^([0-9]{2})-([0-9]{2})-([0-9]{4})$");
     var matches = IsoDateRe.exec(this);
     if (!matches) return false;
     var composedDate = new Date(matches[3], (matches[1] - 1), matches[2]);
     return ((composedDate.getMonth() == (matches[1] - 1)) &&
      (composedDate.getDate() == matches[2]) &&
      (composedDate.getFullYear() == matches[3]));
}

How can I get the above code to work for MM-DD-YYYY and better yet MM/DD/YYYY?

Thanks.

Answer 1

You should include the code you used to test if it worked.

Answer 2

You can simplify it somewhat by changing the first two lines of the function to this:

var matches = this.match(/^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$/);

Or, just change the parameter to the RegExp constructor to be

^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$

Answer 3

what isn't working about it? here's a tested version:

String.prototype.isValidDate = function()   {

    var match   =   this.match(/^([0-9]{2})\/([0-9]{2})\/([0-9]{4})$/);
    var test    =   new Date(match[3], match[1] - 1, match[2]);
    return (
        (test.getMonth() == match[1] - 1) &&
        (test.getDate() == match[2]) &&
        (test.getFullYear() == match[3])
    );
}

var date = '12/08/1984'; // Date() is 'Sat Dec 08 1984 00:00:00 GMT-0800 (PST)'
alert(date.isValidDate() ); // true

Answer 4

I use this regex for validating MM-DD-YYYY:

function isValidDate(subject){
  if (subject.match(/^(?:(0[1-9]|1[012])[\- \/.](0[1-9]|[12][0-9]|3[01])[\- \/.](19|20)[0-9]{2})$/)){
    return true;
  }else{
    return false;
  }
}

It will match only valid months and you can use / - or . as separators.

Answer 5

function isValidDate(date)
{
    var matches = /^(\d{2})[-\/](\d{2})[-\/](\d{4})$/.exec(date);
    if (matches == null) return false;
    var d = matches[2];
    var m = matches[1] - 1;
    var y = matches[3];
    var composedDate = new Date(y, m, d);
    return composedDate.getDate() == d &&
            composedDate.getMonth() == m &&
            composedDate.getFullYear() == y;
}
console.log(isValidDate('10-12-1961'));
console.log(isValidDate('12/11/1961'));
console.log(isValidDate('02-11-1961'));
console.log(isValidDate('12/01/1961'));
console.log(isValidDate('13-11-1961'));
console.log(isValidDate('11-31-1961'));
console.log(isValidDate('11-31-1061'));

It works. (Tested with Firebug, hence the console.log().)