Neil,

A bit more precision may be wise in your request. While sgifford's response is possibly sufficient, it doesn't take into account things like day roll-overs. If you don't need to worry about boundary cases such as 23:00 vs 01:00, that's great. If you do need to worry about those cases, then you'll need to give more information about how you can tell (from a human perspective if you can't describe it in perl). For example, the time difference between 23:00 and 01:00 could be 2 hours, or 22 hours, depending on which comes first. If the second time is always later than the first, then that's information we can use to come up with a more accurate algorithm.

Thanks,

First, tease the time out of the string. Then use Date::Manip's DateCalc() subroutine to compare the two dates, or use the Date::Calc module (probably faster and more targeted to your need).

# No error checking
($s1,$s2)=@ARGV;
print ((abs(minutes($s1)-minutes($s2)) <= 3*60) ?
  "yes\n" :
  "no\n");

sub minutes
{
  my($str)=@_;
  if ($str =~ /(\d+):(\d+)/)
  {
    return $1*60+$2;
  }
  return undef;
}
[download]