ActiveState's ActivePerl is a full Perl distribution that should come complete with all the perl libs you should need - including Date.pm. If not, just pull up a command prompt and type ppm install _name_of_perl_module_to_install and it will install them.
Plus, if you want to see all the modules that ppm can install, run ppm and type "search" at the prompt. (I just tried it and got back a list 97 pages long.)
I don't think you would want to install EVERY Perl module because: