Today (it's 29th February) many phpBB by Przemo forums have blown. It's because of lap year and their "whose birthday is it" function.
Warning. Clicking link below may even make you vomit.
I'm ugly, think again
Yes, they didn't use standard
date("L"), yes they did their own calculations (using
sqrt?!?), and yes, they f*ck*d it badly. Awful switch full of magic numbers (hello, PHP is a junk, but it has loops and arrays) is just a minor ugliness.