# get the epoch seconds for 8:00am the following day
# NOTE if it's after midnight this doesn't work but
# should be trivial to fix
my $now = time();
my ($mday, $mon, $year) = (localtime($now))[3,4,5];
my $then = timelocal(0, 0, 8, $mday + 1, $mon, $year);
my $difference = $then - $now;
sleep($difference);