There are so many date and time modules on CPAN, it's scary. It's similar to the situation with template modules and DBI wrappers. I've been thinking of trying to write "the one true date/time" module, primarily by ripping apart the other modules and producing something that did all the useful things they do, but with a consistent API.
It'd be a cool thing to have, but I'm tired right now. Maybe later in the year.