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Re: Who First Thought Of Using GMT/UTC For System Clock?

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Lawrence D'Oliveiro <ldo@nz.invalid> writes:
> One thing Unix (and its POSIX-based successors) did differently from most 
> other OSes was its system clock was not set to local time, but to UTC (and 
> to GMT, before UTC). This seems pointless if you are accustomed to only 
> dealing with one time zone, but it turned out to be a very elegant idea, 
> that simplified a lot of date/time headaches.
>
> Was Unix the first to come up with this idea? Did some other OS (Multics, 
> perhaps?) pioneer this convention first?

joined ibm science center not long before internal 370 spec. the 370
hardware tod clock was spec'ed GMT since the start of the century. spent
a couple months in discussions about whether start of the century was
1/1/1900 or 1/1/1901 (technically it is 1/1/1901, but lots of places
were setting it to start 1/1/1900, and then found some setting it with
start 1/1/1970). the other big discussion was how to handle "leap
seconds". They finally had to further clarify the public published spec.

trivia: some of the MIT CTSS/7094 people went to project mac for multics
on the 5th flr, others went to the ibm science center on the 4th flr.

from eearly 370 principles of operation.

Thus, the operator can enable the setting of all clocks in the
configuration by using the switch ,of any CPU in the configuration.
time to which a clock value of zero corresponds.  January 1, 1900, 0
A.M. Greenwich Mean Time is recommended as the standard epoch for the
clock, although some early support of the TOD clock is not based on this
epoch.

-- 
virtualization experience starting Jan1968, online at home since Mar1970

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Who First Thought Of Using GMT/UTC For System Clock? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-10-30 00:00 +0000
  Re: Who First Thought Of Using GMT/UTC For System Clock? p.dean@invalid.net (Peter Dean) - 2024-10-30 02:48 +0000
    Re: Who First Thought Of Using GMT/UTC For System Clock? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-10-30 03:11 +0000
      Re: Who First Thought Of Using GMT/UTC For System Clock? p.dean@invalid.net (Peter Dean) - 2024-10-30 03:58 +0000
    Re: Who First Thought Of Using GMT/UTC For System Clock? Chris Ahlstrom <OFeem1987@teleworm.us> - 2024-10-30 07:07 -0400
      Re: Who First Thought Of Using GMT/UTC For System Clock? p.dean@invalid.net (Peter Dean) - 2024-10-30 14:48 +0000
    Re: Who First Thought Of Using GMT/UTC For System Clock? "Carlos E.R." <robin_listas@es.invalid> - 2024-10-30 14:11 +0100
      Re: Who First Thought Of Using GMT/UTC For System Clock? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-10-30 20:54 +0000
        Re: Who First Thought Of Using GMT/UTC For System Clock? scott@slp53.sl.home (Scott Lurndal) - 2024-10-30 22:19 +0000
          Re: Who First Thought Of Using GMT/UTC For System Clock? Bob Eager <news0009@eager.cx> - 2024-10-30 22:26 +0000
          Re: Who First Thought Of Using GMT/UTC For System Clock? Jim Jackson <jj@franjam.org.uk> - 2024-11-08 17:21 +0000
  Re: Who First Thought Of Using GMT/UTC For System Clock? Daniel <me@sc1f1dan.com> - 2024-10-30 13:03 +0000
    Re: Who First Thought Of Using GMT/UTC For System Clock? John Levine <johnl@taugh.com> - 2024-10-30 21:30 +0000
      Re: Who First Thought Of Using GMT/UTC For System Clock? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-10-31 02:14 +0000
    Re: Who First Thought Of Using GMT/UTC For System Clock? Peter Flass <peter_flass@yahoo.com> - 2024-11-03 12:49 -0700
  Re: Who First Thought Of Using GMT/UTC For System Clock? "Carlos E.R." <robin_listas@es.invalid> - 2024-10-30 14:14 +0100
  Re: Who First Thought Of Using GMT/UTC For System Clock? Lynn Wheeler <lynn@garlic.com> - 2024-10-30 09:07 -1000
    Re: Who First Thought Of Using GMT/UTC For System Clock? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-10-30 20:51 +0000
      Re: Who First Thought Of Using GMT/UTC For System Clock? Lynn Wheeler <lynn@garlic.com> - 2024-10-30 13:13 -1000

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