[comp.std.c] Epoch's for time_t

dlm@cuuxb.ATT.COM (Dennis L. Mumaugh) (11/16/88)

In article <27432@tut.cis.ohio-state.edu> lum@bat.cis.ohio-state.edu 
(Lum Johnson) writes:

    The  epoch  you're  referring  to  is   probably   0000   GMT
    17-Nov-1858,  the same as for pdp-10 monitors with which I am
    familiar.  The date was chosen by someone at The  Smithsonian
    Institution  if  I recall correctly; I no longer remember the
    significance, but it was probably when the Gregorian calendar
    was adopted by some official group or major government.

Actually  the  epoch  is  the   founding   of   the   Smithsonian
Institution.  This is logical for cataloging its collection.

I claim there is one "logical" epoch and  that  is  the  one  the
Julian  date  is  based  upon.  It is located back in the time of
early recorded history and is based on the common epoch for  most
historical  calendars.  Suffice  it  to  say any negative date in
that epoch is Soooo old only paleo-archelogoists would need them.
Also it has some nice numerical properties for the current era in
terms of eliminating parts of the date information.

I am sure one can find more information as Julian date  has  been
discussed many times before.
-- 
=Dennis L. Mumaugh
 Lisle, IL       ...!{att,lll-crg}!cuuxb!dlm  OR cuuxb!dlm@arpa.att.com

dmi@peregrine.peregrine.com (Dean Inada) (11/17/88)

In article <2199@cuuxb.ATT.COM> dlm@cuuxb.UUCP (Dennis L. Mumaugh) writes:
 >
 >In article <27432@tut.cis.ohio-state.edu> lum@bat.cis.ohio-state.edu 
 >(Lum Johnson) writes:
 >    The  epoch  you're  referring  to  is   probably   0000   GMT
 >    17-Nov-1858,  the same as for pdp-10 monitors with which I am
 >    familiar.  The date was chosen by someone at The  Smithsonian
 >
 >Actually  the  epoch  is  the   founding   of   the   Smithsonian
 >
 >I claim there is one "logical" epoch and  that  is  the  one  the
 >Julian  date  is  based  upon.  It is located back in the time of

12:00 GMT 16-Nov-1858 is Julian day 2400000.
A very millennial epoch for the founding of the Smithsonian, n'est-ce pas?