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Archiver > TMG > 2001-09 > 0999403588


From: "William M Roberts" <>
Subject: Re: [TMG] Julian dates
Date: Sun, 2 Sep 2001 00:06:28 -0400
References: <004601c13326$c7ac0d80$b64279a5@oemcomputer> <3B9163EE.FCE83B78@infoave.net> <001901c1334c$2a1d9f40$574a79a5@oemcomputer>


Seems like when I was designing systems we had a "Julian" date which was a
combination of the year and the numeric day of the year. Since we were only
interested in dates in the 20th century at that time (Y2K problem) we used
the last two digits of the year and the numeric day of the year such as
75001 for 1 Jan 1975. This was done in order to store data in a minimum
amount of disk space. The largest numeric value we would encounter with this
system was 99365 which we could store in 17 bits (yes we used the number of
bits required for the data). Since we were not interested in dates prior to
around 1950, we created an algorithm to pack the date into 16 bits.
We did not have the luxury of many gigabytes of storage like today and it
was almost a necessity to do this kind of manipulation in order to store
data that had many many dates that items were due.

Myrnice

"Joan Lince" wrote:
> Richard,
> Do you mean besides the ones that Scaliger invented and besides the
> Julian calendar? As a matter of fact, I seem to remember (from my
> pre-retirement days) something about Julian dates that were calculated
from
> January 1, 1900. Is it something like that that you are talking about?
> Joan Lince
>
"Richard Brogger" wrote:
>
> > Hi Joan,
> >
> > There are other "Julian" dates so one has to be careful.
> >
> > Richard
> >
> > Joan Lince wrote:
> > >
> > > Richard,
> > > Thanks for passing along the information about Julian dates. I
> always
> > > thought programmers who talked about the Julian dates that they use
were
> > > showing their ignorance in using the wrong name for a system that had
> > > nothing to do with the Julian calendar. I now wish Joseph Scaliger had
> > > called the system the Scaliger period (or that Scaliger's father had
> been
> > > named Marcus Brutus Scaliger).
> > > As long as we are talking about *wish* lists, maybe it would be
> helpful
> > > if a future version of TMG could both read back to us dates the way
we> > > entered them, and enable us to see (and optionally print) the
results of
> > > calculations based on Julian dates.
> > > Joan Lince



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