Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uflorida!haven!adm!xadmx!RDK%vm.temple.edu@cunyvm.cuny.edu
From: RDK%vm.temple.edu@cunyvm.cuny.edu (Robert Keiser)
Newsgroups: comp.lang.pascal
Subject: Re: day-of-week algorithm
Message-ID: <20771@adm.BRL.MIL>
Date: 1 Sep 89 19:35:53 GMT
Sender: news@adm.BRL.MIL
Lines: 46

On 1 Sep 89 17:32:50 GMT you said:
>I apologize if this has already been discussed, but I recently discovered
>a point of confusion / error (gasp!) in the day-of-week algorithm posted
>here several months ago.
>This article appeared last April (1989):
>
 ...omitted original message...
>  (* the above formula returns  0 for saturday,
>                                1 for sunday,
>                                ...
>                                6 for friday.       *)
>
This is interesting,  When I run it on a Cyber it comes out with the following
results:
                0 = Sunday
                1 = Monday
                ...
                6 = Saturday

I think that I just found the problem.  I apologize for my original posting.
The original algorithm was from a C book so no DIV function.  The text that
accompanied the algorithm clarified things.  The function should look like
this.

 N := ((1461 * F(Year,Month)) DIV 4) + ((153 * G(Month)) DIV 5) + Day;
 DOW := (N - 621049) MOD 7;

When I wrote to the list I just pulled the comments but didn't look at the
code that I wrote to go along with it.
 ... Rest of letter deleted. ...
>
>---Martin Thurn    thurn@cis.ohio-state.edu     73747.224@compuserve.com
>
>Disclaimer: The preceding statements are n...Wait a minute! I AM the company!

I'm suprised it took this long to show up.

Robert Keiser
Systems Analyst
Temple University Computer Activities

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