Date and time
date [ option ] [ seconds ]
Print the date, in the format
Tue Aug 16 17:03:52 CDT 1977
The options are
-u
Report Greenwich Mean Time (GMT) rather than local time.
-n
Report the date as the number of seconds since the epoch, 00:00:00 GMT, January 1, 1970.
The conversion from Greenwich Mean Time to local time depends on the $timezone environment variable; see ctime(3).
If the optional argument seconds is present, it is used as the time to convert rather than the real time.
\*9/src/cmd/date.c