1--TEST-- 2Bug #73460 (Datetime add not realising it already applied DST change) 3--FILE-- 4<?php 5$date = new DateTime('2016-11-05 23:45:00', new DateTimeZone('America/New_York')); 6 7foreach (range(1, 20) as $i) { 8 echo $date->format('Y/m/d H:i e T'), "\n"; 9 10 $date->add(new DateInterval('PT15M')); 11} 12?> 13--EXPECT-- 142016/11/05 23:45 America/New_York EDT 152016/11/06 00:00 America/New_York EDT 162016/11/06 00:15 America/New_York EDT 172016/11/06 00:30 America/New_York EDT 182016/11/06 00:45 America/New_York EDT 192016/11/06 01:00 America/New_York EDT 202016/11/06 01:15 America/New_York EDT 212016/11/06 01:30 America/New_York EDT 222016/11/06 01:45 America/New_York EDT 232016/11/06 01:00 America/New_York EST 242016/11/06 01:15 America/New_York EST 252016/11/06 01:30 America/New_York EST 262016/11/06 01:45 America/New_York EST 272016/11/06 02:00 America/New_York EST 282016/11/06 02:15 America/New_York EST 292016/11/06 02:30 America/New_York EST 302016/11/06 02:45 America/New_York EST 312016/11/06 03:00 America/New_York EST 322016/11/06 03:15 America/New_York EST 332016/11/06 03:30 America/New_York EST 34