I'm creating a small reporting script in Perl CGI. I want to have the start/end date there to filter the events on the report. So now I wonder how to validate the input in some easy, Perl-way. 

The way I generate the form with those fields is:

```
    print textfield({-name=>'start_date', -value=>$start_date});
    print textfield({-name=>'end_date', -value=>$end_date});

```

Then it goes to the database query. 

Is there a simple, Perl-ish way to validate those dates? Not only as having the right number of characters, as this is simple enough via a regexp, but I'd like to report some error if the user enters 29.02.1999 or so.