A. that's super funky use of
sprintf
B. you really need to take a look at POSIX::strftime and it's red headed brother, POSIX::strptime. Both give you the same feels as sprintf if that's what you're needing
I mark my journey as a programmer by moments of sheer awe when I discover something awesome. That combo is one of those times. The other was when I first learned to create a mailto: link in my college computer lab in the 90s. These 2 events were roughtly 19 years apart and the ones that stick out most in my mind. Good luck.