leap seconds

[...] POSIX is a ``standard'' designed by a vendor consortium several years ago to eliminate progress and protect the installed base. The behavior of the broken localtime() libraries was documented and turned into a POSIX requirement.

Fortunately, the POSIX rules are so outrageously dumb---for example, they require that 2100 be a leap year, contradicting the Gregorian calendar---that no self-respecting engineer would obey them.