use Date::Manip;

my @dayOfWeek = qw(Sunday Monday Tuesday Wednesday Thursday Friday Sat
+urday);
my ( $month, $day, $year ) = ( 5, 25, 2002 );
my $day = &Date_DayOfWeek( $month, $day, $year );
print $dayOfWeek[ $day ];
[download]

And no doubt somebody is going to look that date up and say that it is not a Monday... =8-)

Cheers,
Ovid

Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.

An alternative to Date::Manip is the Date::Calc module which also provides hordes of date utility functions (and it is a C lib so it is fairly quick).

#!/usr/bin/perl -w
use strict;
use Date::Calc qw/Day_of_Week/;

my @days = qw/Sunday Monday Tuesday Wednesday
              Thursday Friday Saturday/;

my $dow = $days[ Day_of_Week(2002, 5, 25) ];
print "$dow\n";
__END__
[download]

Several have mentioned simple ways to do it yourself, but if you need more date manipulation than your post suggests (things like differences between dates, business days, etc), I recommend checking out one of the modules -- it isn't hard to work with dates, but it isn't hard to work with dates incorrectly either :-)

1.) use Time::Local
- with the help of this module you can convert the date (may 25 2002) to Unix time.
2.) and then localtime($your_unix_time) will give you the weekday (check localtime manual)

-- tune

   use Date::Manip
    
   $day=&Date_DayOfWeek($m,$d,$y);
[download]

If you have any funny date/time stuff that you want to do, a good first step is always "perldoc Date::Manip" because most likely it can do exactly what you want.

use Time::ParseDate;
use Time::CTime;

my $day_of_week=strftime("%A",localtime(parsedate("May 25, 2002")));
[download]

use Time::Local;
$day = unpack"a3",localtime timelocal 0,0,12,25,5-1,2002-1900;
[download]

Or use Date::Format; and say time2str("%A",$time);

You did want Saturday, right?

Update: I got ahead of myself. time2str uses a epoch time which you could get from timelocal. Turns out, I should have used
strftime("%A", ['','','',25,05,2002]);

ALL HAIL BRAK!!!

Um, what do I do for that localtime() part??
Or Psycho, what does $time hold?

Could you give me the code, I'm slow.

Update: Hey, isn't the Date module standard??
I have to install the stupid thing... Unbelievable!

While I strongly suggest taking cat2014's advice... The localtime function converts an Epoch date into a list. If you look at the documentation, it has (IIRC) nine elements, of which one is the number of the day of the week ($wday). Which you can then use to extract the day of the week from your own @days = ( Sun, Mon, Tue, Wed, Thu, Fri, Sat) list, using $days[$wday]. Update: Getting your input date into Epoch time without a module like Date::Manip, however, is tricky as all heck and not recommended.