May 26, 2018
Efficiently compute time from local and GMT time
These routines are the inverse of built-in perl functions localtime and gmtime. They accept a date as a six-element array, and return the corresponding time2 value in seconds since the system epoch Midnight, January 1, 1970 UTC on Unix, for example. This value can be positive or negative, though POSIX only requires support for positive values, so dates before the system’s epoch may not work on all operating systems.