Task
 
Choose popular date libraries used by your language and show the   epoch   those libraries use.

A demonstration is preferable   (e.g. setting the internal representation of the date to 0 ms/ns/etc.,   or another way that will still show the epoch even if it is changed behind the scenes by the implementers),   but text from (with links to) documentation is also acceptable where a demonstration is impossible/impractical.

For consistency's sake, show the date in UTC time where possible.



Related task

   Date format


       IDENTIFICATION DIVISION.
       PROGRAM-ID. epoch.
 
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01  epoch-date.
           03  year                PIC 9(4).
           03  month               PIC 99.
           03  dday                PIC 99.
 
       PROCEDURE DIVISION.
           MOVE FUNCTION DATE-OF-INTEGER(1) TO epoch-date
 
           DISPLAY year "-" month "-" dday
 
           GOBACK
           .