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lib/Date/SundayLetter.pm  view on Meta::CPAN

        $letter = $letters[$d];
    }

    return $letter;
} #}}}

# sub parameter {{{

sub parameter {
# The "parameter" is a magic number that tracks how far the Gregorian
# calendar is from the Julian calendar. It has roughly to do with the
# fact that the Gregorian calendar observes leap year on the 4-century
# mark, and the Julian calendar does not.
    my $year = shift;

    my $S = int ($year / 100 );
    my $P = ( int( $S/4 ) - $S ) % 7;

    return $P;
} # }}}

1;