This skip logic can be used to skip respondents to a terminate page if they attempt to take the survey outside of the acceptable time range.
Begin Unverified Perl
my ($second, $minute, $hour, $day, $month, $year, $weekDay, $yearDay, $isDst) = gmtime(time);
my $closed = $hour <= 4 || $hour >= 16;
The times on line 3 can be updated. Keep in mind that these times are GMT, so be sure to account for your timezone difference.