diff --git a/phpBB/includes/functions_user.php b/phpBB/includes/functions_user.php
index 3a77407c20..f235b2be55 100644
--- a/phpBB/includes/functions_user.php
+++ b/phpBB/includes/functions_user.php
@@ -197,7 +197,6 @@ function user_add($user_row, $cp_data = false)
 		'user_lastpost_time'	=> 0,
 		'user_lastpage'			=> '',
 		'user_posts'			=> 0,
-		'user_dst'				=> (int) $config['board_dst'],
 		'user_colour'			=> '',
 		'user_occ'				=> '',
 		'user_interests'		=> '',
@@ -677,8 +676,10 @@ function user_ban($mode, $ban, $ban_len, $ban_len_other, $ban_exclude, $ban_reas
 			if (sizeof($ban_other) == 3 && ((int)$ban_other[0] < 9999) &&
 				(strlen($ban_other[0]) == 4) && (strlen($ban_other[1]) == 2) && (strlen($ban_other[2]) == 2))
 			{
-				$time_offset = (isset($user->timezone) && isset($user->dst)) ? (int) $user->timezone + (int) $user->dst : 0;
-				$ban_end = max($current_time, gmmktime(0, 0, 0, (int)$ban_other[1], (int)$ban_other[2], (int)$ban_other[0]) - $time_offset);
+				$ban_end = max($current_time, $user->create_datetime()
+					->setDate((int) $ban_other[0], (int) $ban_other[1], (int) $ban_other[2])
+					->setTime(0, 0, 0)
+					->getTimestamp() + $user->tz->getOffset(new DateTime('UTC')));
 			}
 			else
 			{
diff --git a/phpBB/includes/ucp/ucp_register.php b/phpBB/includes/ucp/ucp_register.php
index aee55711b2..ac002a26c2 100644
--- a/phpBB/includes/ucp/ucp_register.php
+++ b/phpBB/includes/ucp/ucp_register.php
@@ -120,7 +120,10 @@ class ucp_register
 			if ($coppa === false && $config['coppa_enable'])
 			{
 				$now = getdate();
-				$coppa_birthday = $user->format_date(mktime($now['hours'] + $user->data['user_dst'], $now['minutes'], $now['seconds'], $now['mon'], $now['mday'] - 1, $now['year'] - 13), $user->lang['DATE_FORMAT']);
+				$coppa_birthday = $user->create_datetime()
+					->setDate($now['year'] - 13, $now['mon'], $now['mday'] - 1)
+					->setTime(0, 0, 0)
+					->format($user->lang['DATE_FORMAT'], true);
 				unset($now);
 
 				$template->assign_vars(array(
@@ -163,7 +166,6 @@ class ucp_register
 			$captcha->init(CONFIRM_REG);
 		}
 
-		$is_dst = $config['board_dst'];
 		$timezone = $config['board_timezone'];
 
 		$data = array(
@@ -280,7 +282,6 @@ class ucp_register
 					'user_email'			=> $data['email'],
 					'group_id'				=> (int) $group_id,
 					'user_timezone'			=> $data['tz'],
-					'user_dst'				=> $is_dst,
 					'user_lang'				=> $data['lang'],
 					'user_type'				=> $user_type,
 					'user_actkey'			=> $user_actkey,