I've kinda given up on "validation" of dates. I usually use something like

use Date::Manip;
my $formatted_date = UnixDate $date, $PREFERRED_FORMAT;
[download]

If Date::Manip::UnixDate() can figure out what was provided enough to produce a date in the format that I wish, then it was good enough. It isn't the fastest approach in the world, but it has served me well.

- doug