sub isLeapyear
{
	my ($year, @extraStuff) = @_;
	if (!defined $year) { $year = 0; }
	
	my $leapYearFlag = 0;		# Assume not a leap year until proven otherwise.

	if ($year % 4) {
		# Not divisible by 4.  Cannot be a leap year.
		$leapYearFlag = 0;
	} else {
		# Divisible by 4.  Possibly a leap year.
		if ($year % 100) {
			# Is not divisible by 100.  It is a leap year.
			$leapYearFlag = 1;
		} else {
			# Is divisible by 100.  May not be a leap year.
			if ($year % 400) {
				# Is not divisible by 400.  Cannot be a leap year.
				$leapYearFlag = 0;
			} else {
				# Is divisible by 400.  IS a leap year.
				$leapYearFlag = 1;
			}
		}
	}

	return $leapYearFlag;
}