BUG #6420: Incorrect description of Postgres time system

The following bug has been logged on the website:

Bug reference: 6420
Logged by: Thomas McGlynn
Email address: tom(dot)mcglynn(at)nasa(dot)gov
PostgreSQL version: 9.1.2
Operating system: Any
Description:

As part of our preparations for the leap second this year I wanted to see
how Postgres handles this. The only information I could see was

(Technically, PostgreSQL uses UT1 because
leap seconds are not handled.)

in section 9.9 of the manual. This seems to be a misapprehension of what
the UT1 time system is. UT1 measures mean solar time -- days are not
exactly 86400 seconds long. Currently UT1 and UTC never differ by more than
one second. Leap seconds are the way this correspondence is kept. What I
believe you should be saying is that you use TAI -- atomic time -- with some
offset.

If my inferences from the documentation is correct and Postgres measures the
number of seconds from UTC 2000-01-01, then the time system used is TAI-32
seconds. See http://stjarnhimlen.se/comp/time.html for details (and to
check whether I got the sign right!).

I think this should be clearly stated in the documentation when discussing
the time types but I did not see it.

Regards...