##
##  Convert an integer number of seconds into a 
##  formatted ddd:hh:mm:ss string.
##
sub s2d
{	
	use integer;

	my $s = shift;  
	return sprintf ":%02d", $s if $s < 60;

	my $m = $s / 60; $s = $s % 60;
	return sprintf "%02d:%02d", $m, $s if $m < 60;

	my $h = $m /  60; $m %= 60;
	return sprintf "%02d:%02d:%02d", $h, $m, $s if $h < 24;

	my $d = $h / 24; $h %= 24;
	return sprintf "%d:%02d:%02d:%02d", $d, $h, $m, $s;
}

##
##  Is year a leap year?
##
sub is_leap
{
	my ($yy);
	($yy)=@_;

	if ($yy % 4 == 0 and ($yy % 100 != 0 or $yy % 1000 == 0)) {
		return 0;
	} else {
	        return 1;
	}
}