[LEAPSECS] The POSIX Time Rationale - in the Working Group's own words

[Joseph Gwinn]

It may prove useful to know why the POSIX Working Group (WG) excluded 
leap seconds, in their own words.  

See section A.4.16 "Seconds Since the Epoch" in the following webpage:

.<http://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap04.html>


Also, we get the definition of Epoch from 
<http://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xbd_chap03.html#tag_21_03_00_20>.  
One can also follow the link from A.4.16.  

The full definition is short, so I repeat it below:

Epoch - "Historically, the origin of UNIX system time was referred to 
as "00:00:00 GMT, January 1, 1970". Greenwich Mean Time is actually not 
a term acknowledged by the international standards community; 
therefore, this term, "Epoch", is used to abbreviate the reference to 
the actual standard, Coordinated Universal Time."

What they are clumsily saying above is to replace GMT with UTC in the 
historical definition, so the current definition is "00:00:00 *UTC*, 
January 1, 1970".  The WG knew full well that GMT and UTC are not 
exactly equal, but considered the resulting error (81 microseconds, if 
memory serves) insignificant.

Joe Gwinn