asked on

Compare two mmddyyyy dates in JavaScript

I need to compare two dates in JavaScript that are entered as MMDDYYYY and throw an error if one is before the other.

In the .js file, any chars are stripped out from the two fields.

var cmDateOfInjury = stripCharsNotInBag (form.cmDateOfInjury.value, "1234567890");
form.cmDateOfInjury.value = cmDateOfInjury;
var cmDateNotify = stripCharsNotInBag (form.cmDateNotify.value, "1234567890");
form.cmDateNotify.value = cmDateNotify;

The cmDateNotify cannot be before the cmDateOfInjury. How do I convert the dates and compare?

Gary

Are the dates exactly like MMDDYYYY i.e. no seperators?

Lee

I'd jiggle with the strings first.

Make them in the form yyyymmdd and then do an integer compare.

eg

<script>

var doi = "12252013";
var don = "12302013";

doi = doi.substring(4) + doi.substring(0, 4);
don = don.substring(4) + don.substring(0, 4);

if(parseInt(don) < parseInt(doi))
  document.write("invalid, notify date cannot be earlier");
else
  document.write("this is ok");


</script>

Open in new window

ASKER CERTIFIED SOLUTION

Lee

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

roosterup

ASKER

Yes, the dates are MMDDYYYY with no separators.

Gary

lsavidge has given you a nice easy solution for your case then.

roosterup

ASKER

awesome.

Lee

Thanks :)

Whenever playing dates and you're doing a date comparison, I always and I mean I ALWAYS, convert to an integer and compare. It's a lot easier to do in code. Put some comments in the code because sometimes it may be a bit weird to someone that doesn't use this method.

It makes sorting lists of dates a doddle as well.