CPAN is your friend.
Storable: persistency for perl data structures - that wasn't so hard, was it?

Couldn't find anything on Integer_DateTime, but I've only spent 5 seconds looking.

Update: OK, after spending a minute or so searching for info on Integer_DateTime, I gave up.
ddrumguy, can you post a link to the script so we can have a look at what it's doing?

Further Update: The AnonyMonk's post below is pretty much what I suspect - some sort of module the author of the script has written to support it.
It should be noted, however, that not every module on CPAN is of the form Group::Function (i.e. Net::POP3) - CGI and the aforementioned Storable are obvious exceptions.