Test a value to see if is valid and can be represented here.
The standard Unix time is a signed integer data type, directly encoding the Unix time number, which is the number of seconds since 1970-01-01. Being 32 bits means the values here cover a range of about 136 years. The minimum representable time is 1901-12-13 20:45:52, and the maximum representable time is 2038-01-19 03:14:07.