get number of seconds to sleep for once a day scheduling by hour

sleepseconds.pl

sub getsleep {
	my ($thour) = @_;

	return 0 unless $thour;

	my ( $sec, $min, $hour, $mday, $mon, $year, $wday, $yday, $isdst )
		= localtime(time);
	my $dif = $thour - $hour - $min / 60 - $sec / 3600;
	if ( $dif >= 0 ) {
		return $dif * 3600;
	}
	else {
		return ( 24 + $dif ) * 3600;
	}
}