- date_interval_create_from_date_string: documentation ( source)
- date_create_from_format: documentation ( source)
<?php
$a = date_create_from_format('Ymd H:i','20141001 27:05')->sub( date_interval_create_from_date_string('1 minutes') );
print '20141002 03:05';print"\n";
print $a->format('Ymd H:i');