Sometimes we need subsecond precision. Yes, but "time_t"s need not provide subsecond precision; 4.[23]BSD-style "struct timeval" may not be ideal, but they do the job. Sometimes we care about things that happened in the 19th century (birthdates, for example.) Yes, but nothing in a UNIX system happened in the 19th century. Non-UNIX systems lacking "time_t" have done quite well dealing with times; I don't see any need to use "time_t" for every kind of timestamp any application could possibly want. It might be aesthetically "nice" to have the time representation used by the OS be the same that would be used by every conceivable application, but I don't see that it's worth the effort of changing what a "time_t" is. (There are plenty of OSes out there with the same problem; the VMS epoch starts 00:00 - local time, I believe - November 17, 1858.)