<?php
$data1 = '2018-01-09 16:14:01';
$data2 = '2018-01-09 17:30:04';
$nHoras = ($unix_data2 - $unix_data1) / (60 * 60);
$nMinutos = (($unix_data2 - $unix_data1) % (60 * 60)) / 60;
printf('%02d:%02d', $nHoras, $nMinutos);
PD9waHAKCiRkYXRhMSA9ICcyMDE4LTAxLTA5IDE2OjE0OjAxJzsKJGRhdGEyID0gJzIwMTgtMDEtMDkgMTc6MzA6MDQnOwoKJHVuaXhfZGF0YTEgPSBzdHJ0b3RpbWUoJGRhdGExKTsKJHVuaXhfZGF0YTIgPSBzdHJ0b3RpbWUoJGRhdGEyKTsKCgokbkhvcmFzICAgPSAoJHVuaXhfZGF0YTIgLSAkdW5peF9kYXRhMSkgLyAoNjAgKiA2MCk7CiRuTWludXRvcyA9ICgoJHVuaXhfZGF0YTIgLSAkdW5peF9kYXRhMSkgJSAoNjAgKiA2MCkpIC8gNjA7CgpwcmludGYoJyUwMmQ6JTAyZCcsICRuSG9yYXMsICRuTWludXRvcyk7Cg==