use Time::Local;
use strict;

sub waityourturn {
  my $now = time;
  my $twohours = 60*60*2;
  my $onehour = 60*60;

  my ($sec,$min,$hour,$mday,$mon,$year) = localtime($twohours+$now);

  if ($hour  % 2 == 0) { # if hour is even, let's just add one hour
   ($sec,$min,$hour,$mday,$mon,$year) = localtime($onehour+$now);
  }

  $sec = 0;
  $min = 30;
  my $target_time = timelocal($sec,$min,$hour,$mday,$mon,$year);
  my $naptime = $target_time - time;

  print "I am going to sleep $naptime seconds until ", 
      scalar(localtime($target_time)), "\n";
  sleep($naptime);
}
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