use strict;

my ($beg, $end) = qw(00:01:20 00:02:20);
print "beg: $beg   end: $end\n";

print "Matches\n--------\n";
while (<DATA>) {
  chomp;
  if (($_ ge $beg) && ($_ le $end)) {
     print "$_\n";
  }
}

__DATA__
00:01:01
01:01:01
00:01:20
00:01:21
00:02:00
00:02:21
00:02:20
00:01:19

##</code><code>##

beg: 00:01:20   end: 00:02:20
Matches
--------
00:01:20
00:01:21
00:02:00
00:02:20