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From: jessea@dynasys.UUCP (Jesse W. Asher)
Newsgroups: comp.mail.uucp
Subject: Re: UUCP status files and wierd dates - revisted.
Message-ID: <756@dynasys.UUCP>
Date: 26 Nov 90 16:01:24 GMT
References: <736@dynasys.UUCP> <803@sci34hub.UUCP> <754@dynasys.UUCP> <1990Nov22.024607.7474@decuac.dec.com>
Reply-To: jessea@dynasys.UUCP ()
Organization: Dynasys:  Consulting for the Future.
Lines: 39

In article <1990Nov22.024607.7474@decuac.dec.com>, mjr@hussar.dco.dec.com (Marcus J. Ranum) wrote the following:
>In article <754@dynasys.UUCP> jessea@dynasys.UUCP () writes:
>
>>WHY is this date used?  WHY can't the beginning of the year be used instead?
>
>	What about stuff that's older than Jan 1, 1990? I have some
>stuff from back then... Should we start dating it in negative time?
>And, once we've laboriously converted every single database, file, and
>whatnot that we have that contains a date, are we supposed to do it
>all over again Jan 1, 1991?

How does the system know how many seconds there are from 1970?  You tell it.
If it can calculate the number of seconds from Jan 1, 1970 it will know
whether it is 1990 or 1991.  As a matter of fact, I mentioned before that
the only problem I saw was that of leap years - but the current implementation
takes this into account so it shouldn't be a problem.  If some arbitrary point
in time can be used for all this, some other point in time can be chosen as
well.  As for dates needed before the current year, something else will have
to be done.  I have no idea what.  I know it sounds bizarre, but using a
negative number only for those programs that need it may not be such a bad
idea.  The only problem is that you might cut your possible dates back in
half (what is the number for the date stored as anyway?).  It just
doesn't seem to me to be very elegant to calculate from a twenty year
old date every time you need a date.  I really know nothing about this -
I'm just trying to find out and so far I still haven't had my question
answered.  In less than five years we will be calculating a 25 year old 
date and the total number will be approxiamately 817314005(approximation
of Nov. 26 1995).  How much total resources - both individual systems 
and all unix systems put together - would be saved if we only had to 
calculate a date using a maximum of approxiamately 31536000 seconds 
instead of that astronomical sum above.  Would it really make that much 
of a difference?

-- 
      Jesse W. Asher                             Phone: (901)382-1609 
               6196-1 Macon Rd., Suite 200, Memphis, TN 38134
                UUCP: {fedeva,chromc,rutgers}!dynasys!jessea