Oct 31 == Dec 25
It’s an octal joke. John Lim over at PHP Everywhere had to chase a bug report because in PHP tossing a zero in front makes your number octal, the way 0x makes you hexadecimal.
Octal notation can be useful for things like filemasks, but I can’t think of many other practical (non-bit fiddling) uses, so school me on it please.
A common PHP mistake is forgetting the chmod() function wants an octal number as the file mode. I wrote about this and some other fun screwups when I worked for Zend in an article called PHP Gotchas, which could really use a part two..