Uses perl core util "date"
date isn't a "perl core util", it's an external operating system command. It's a bad idea to use external commands if they aren't necessary because a) you can never be sure what external commands will be available if you have to move your program to another platform and b) opening a new shell unnecessarily is inefficient. Perl contains everything you need to handle dates. There is no need to use external programs.
"The first rule of Perl club is you do not talk about
-- Chip Salzenberg