<?php
$additional_time = '3:02:30';
$additional_seconds = strtotime('1970-1-1 ' . $additional_time); $format = 'Y-m-d H:i:s';
$future = time() + $additional_seconds;
echo date($format) . PHP_EOL
; echo date($format, $future);
PD9waHAKCgokYWRkaXRpb25hbF90aW1lID0gJzM6MDI6MzAnOwoKJGFkZGl0aW9uYWxfc2Vjb25kcyA9IHN0cnRvdGltZSgnMTk3MC0xLTEgJyAuICRhZGRpdGlvbmFsX3RpbWUpOwokZm9ybWF0ID0gJ1ktbS1kIEg6aTpzJzsKJGZ1dHVyZSA9IHRpbWUoKSArICRhZGRpdGlvbmFsX3NlY29uZHM7CgoKZWNobyBkYXRlKCRmb3JtYXQpIC4gUEhQX0VPTDsKZWNobyBkYXRlKCRmb3JtYXQsICRmdXR1cmUpOwo=