Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!thumper!ulysses!ucbvax!INDYVAX.BITNET!IMHW400
From: IMHW400@INDYVAX.BITNET
Newsgroups: comp.os.vms
Subject: Re:  The ongoing DST debate: a stupid suggestion
Message-ID: <8806030655.AA02624@ucbvax.Berkeley.EDU>
Date: 31 May 88 20:45:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 36

Ralph Becker-Szendy (RALPH@UHHEPG) (facetiously) suggests setting the system
time to UT regardless of the local time zone, and John Hascall (GA.JPH@ISUVMS)
responds with a serious proposal to:

o       keep the clock in UT regardless of time zone;

o       add SYSGEN parameters to specify the standard and DST offsets from
        UT to local time, and the dates between which DST applies;

o       mods to system services, which allow us to control the type of
        conversion applied to binary times.

I approve.  This sort of thing has worked well in TOPS-20 for some time.
However, as stated Mr. Hascall's proposal fails to deal with the problem
of DST in the *past*.  (TOPS-20 also fails to deal with this.)  In other
words, if I want to convert a date-time from *last* year, when the DST Sundays
were different (not just different dates, but different "n'th" Sundays),
should we use this year's dates, or remember last year's?  An ugly problem,
but manageable if we keep a table of (DST-on-Sunday-n,DST-off-Sunday-n,year).
(I didn't invent this method; it was proposed on the TOPS-20 wizards'
newsgroup.)  The algorithm to determine the n'th Sunday in a given year
is not too difficult.

Is it worth dragging around an ever-lengthening table, so that we can
correctly convert past dates?  I think so, as long as the table doesn't
lengthen *too* frequently.  Your thoughts?

Also, can anybody comment on the rumored overhaul of the date-time services
for VMS 5.0?  Has all this been done already, and are we wasting bandwidth
on a non-issue?  Inquiring minds want to know.
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Mark H. Wood    IMHW400@INDYVAX.BITNET   (317)274-0749 III U   U PPPP  U   U III
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