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From: sjw <simon.j.wright@mac.com>
Newsgroups: comp.lang.ada
Subject: Re: Newbie Q: How to program in UTC (time/calendar) ?
Date: Thu, 26 Mar 2009 13:58:56 -0700 (PDT)
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On Mar 26, 1:38=A0am, tmo...@acm.org wrote:
> >I know this is what Windows[1] does, but it isn't what a Real OS (tm)
> >would do
>
> =A0 What do you mean by "this"? If you mean that a "Real OS (tm)" can tel=
l
> where the computer it's running on is located, or what the politicians
> have decided about Daylight Savings time, without being told, that's quit=
e
> magical.
> =A0 You still haven't said how today's clock time relates to your process=
ing
> of time-stamped historical data.

What I mean is that one should keep the internal clock set to UTC (I'm
not being picky about leap seconds here, if the OP needs to be that
will perhaps be more complicated) and change the time zone setting to
correspond to the time zone in which one finds oneself.

The last time I ran Windows outside a virtual environment it would
change the system (bios) clock on DST change. I don't know what it
does if you change the TZ.

TZ/DST info updates (caused by political changes) appear magically
through the ether from one's OS vendor.