Article 12042 of comp.lang.perl:
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From: mbeattie@black.ox.ac.uk (Malcolm Beattie)
Subject: Re: Help:  Needs DayOfWeek on a given day
Message-ID: <1994Mar28.092204.287@black.ox.ac.uk>
Originator: mbeattie@black
Organization: Oxford University Computing Services, Oxford, U.K.
References: <PLEUNG.94Mar24161149@kaon.mpr.ca>
Distribution: comp
Date: Mon, 28 Mar 1994 09:22:04 GMT
Lines: 25

In article <PLEUNG.94Mar24161149@kaon.mpr.ca> pleung@kaon.mpr.ca (Peter Leung) writes:
>Hi, 
>
>I'm a relatively new PERL user.  
>
>I need to determine the DAY of Week for any given day, eg., Jan 10, 1994.
>
>Do I need to write a C program?  
>
>Can I use PERL's localtime and how do I compose the time input needed for localtime?

Set $d to date (1-31), $m to month (1-12), $y to year (e.g. 1994). Then

@d = (0,3,2,5,0,3,5,1,4,6,2,4);
@day = (Sun, Mon, Tue, Wed, Thu, Fri, Sat);
$y-- if $m < 3;
$day = $day[($y+int($y/4)-int($y/100)+int($y/400)+$d[$m-1]+$d) % 7];

$day gives the day.

--Malcolm
-- 
Malcolm Beattie <mbeattie@black.ox.ac.uk>
Oxford University Computing Services
"Widget. It's got a widget. A lovely widget. A widget it has got." --Jack Dee