Calculating Easter

				
=**************************************
= Name: Calculating Easter
= Description:Ever wondered how to Calculate the date of easter? Well here's a simple Perl script that will just do that. It shows how to get the date of Easter for the current year and for the next 25 Years in the Future.
= By: Randy McCleary
=
= Inputs:Year
=
= Returns:Date Of Easter
=
= Assumes:The algorithm is based on the algorithm of Oudin (1940) and quoted in "Explanatory Supplement to the Astronomical Almanac", P. Kenneth Seidelmann, editor.
=
=This code is copyrighted and has= limited warranties.Please see http://www.Planet-Source-Code.com/vb/scripts/ShowCode.asp?txtCodeId=460&lngWId=6=for details.=**************************************

#!/usr/bin/perl -w
########################################################################
# A Simple script that Calculates the date of Easter and shows how
# to calculate future dates of easter.
########################################################################
use POSIX;
use strict;
use CGI qw(:standard);
use CGI::Carp qw(fatalsToBrowser);
use Time::Local;
my ($Year2, $Century, $G, $K, $I, $J, $L, $EasterMonth, $EasterDay, $p);
my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = 0;
($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
my $month_name= 'jan';
$year += 1900;
if (param()) {
	$year = param('y');
}
print header;
print "<b>\n";
######################################
# Print Date of easter This year
######################################
&CalculateEaster();
print "</b><br><br>\n";
######################################
# Print the next 25 Years of Easter
######################################
print "Next 25 Years<br>\n";
for ($p = 1; $p <= 25; $p += 1) {
	&CalculateEaster();
}
######################################
# Subroutine to Calculate the date of
# Easter for a given year
######################################
sub CalculateEaster {
	$Year2 = $year + $p;
	$Century = int $Year2 / 100;
	$G = $Year2 % 19;
	$K = int (($Century - 17) / 25);
	$I = ($Century - int ($Century / 4) - int (($Century - $K) / 3) + 19 * $G + 15) % 30;
	$I = $I - (int ($I / 28)) * (1 - (int ($I / 28)) * (int (29 / ($I + 1))) * (int ((21 - $G) / 11)));
	$J = ($Year2 + int ($Year2 / 4) + $I + 2 - $Century + int ($Century / 4)) % 7;
	$L = $I - $J;
	
	$EasterMonth = 3 + int (($L + 40) / 44);
	$EasterDay = $L + 28 - 31 * (int ($EasterMonth / 4));
	
	$month_name = ("January", "February", "March", 
							"April", "May", "June", "July", 
							"August", "September", "October", 
							"November", "December")[$EasterMonth-1];
					
	print "Easter is $month_name $EasterDay, $Year2 <br>\n";
}