tvb@LeapSecond.com said: > 32-bit integers is sufficient. Use days instead of seconds. Use MJD instead > of JD. Here's an example: I think it depends on how far forward or back in time you want to go. POSIX keeps track of time using seconds since 1970. 31 bits works until 2038. POSIX also pretends that leap seconds don't exist. That makes how-many-days or 3-days-from-X easy to calculate but it's impossible to talk about the individual leap seconds -- they don't exist. -- These are my opinions. I hate spam.