sub addTimes {
  return(sprintf("%d %d:%d:%d", $d=int(($ts=((@ta=split(':', $_[0]))[0]*3600+$ta[1]*60+$ta[2]+(@tb=split(':', $_[1]))[0]*3600+$tb[1]*60+$tb[2]))/86400), $h=int(($ts=$ts-($d*86400))/3600), $m=int(($ts=$ts-($h*3600))/60),$s=int(($ts=$ts-($m*60))/60)));
}

print addTimes('13:45:23', '14:12:43') . "\n";