Comment UNIX time vs TAI (Score 1) 376
Not so. UNIX time is strictly defined in POSIX, as are the arithmetic relationships between it and human time, e.g. a time_t % 60 gives you the elapsed seconds in the current minute, which would not be true if unix time included leap seconds.
What you are describing is TAI, or International Atomic Time. If you were to choose to run your system on TAI, you would need some conversion routines if you wanted your system to remain POSIX compatible (which is what modern unix/linux apps expect) -- e.g. time() and stat() would need to continue to report unix-time values, and you'd need TAI-compliant library functions to request the equivalent items with their raw TAI values.
For more details, see the Wikipedia entry on Unix time.