use Time::Piece;
  $t = Time::Piece->strptime('%T', $time_string);

##</code><code>##

  $seconds = $t2 - $t1;
  print "Diff (secs): ", $seconds->seconds, "\n";

##</code><code>##

   $total_secs = $s2 + $s1;
   print "Secs: ", $total_secs->seconds, "\n";