sub clock_bugfix {
  my $minutes = shift;
  my $sign = ($minutes >= 0);
  my $hh = int($minutes/60);
  my $rest = abs($minutes - $hh*60);
  $hh *= -1 if($hh < 0);
  return sprintf ("%s%d:%02d", ($sign ? '' : '-'), $hh, $rest);
}