There is a module called Data::FormValidator::Constraints::DateTime that is used with Data::FormValidator. You can use this to validate the date that you are trying to do.

The reason that this is better than a regular expression is that you can have a valid regular expression and an invalid date. Example: 02/31/2007. This date just cannot exist. Something trickier would be 02/29/2007. Now you have evaluate if it is a leap year or not.

So use a pre-existing module to validation instead of a regular expression or one of your own. The module I showed up may not be the best option for you but I am sure that there are others out that you might be more comfortable with.