diff --git a/admin/modules/user/mass_mail.php b/admin/modules/user/mass_mail.php
index 7dd5f95315..c607bbbea1 100644
--- a/admin/modules/user/mass_mail.php
+++ b/admin/modules/user/mass_mail.php
@@ -82,7 +82,7 @@
 	$html_personalisation = substr($html_personalisation, 0, -2)."');\n// --></script>\n";
 	$text_personalisation = substr($text_personalisation, 0, -2)."');\n// --></script>\n";
 
-	$localized_time_offset = $mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
+	$localized_time_offset = (float)$mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
 	
 	// All done here
 	if($mybb->request_method == "post")
@@ -615,7 +615,7 @@ function insertText(value, textarea)
 
 	$plugins->run_hooks("admin_user_mass_email_send_start");
 	
-	$localized_time_offset = $mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
+	$localized_time_offset = (float)$mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
 
 	if($mybb->input['step'] == 4)
 	{
diff --git a/admin/modules/user/users.php b/admin/modules/user/users.php
index c6ae013f43..67508b2603 100644
--- a/admin/modules/user/users.php
+++ b/admin/modules/user/users.php
@@ -1024,11 +1024,11 @@
 	$reg_date = my_date('relative', $user['regdate']);
 	if($user['dst'] == 1)
 	{
-		$timezone = $user['timezone']+1;
+		$timezone = (float)$user['timezone']+1;
 	}
 	else
 	{
-		$timezone = $user['timezone'];
+		$timezone = (float)$user['timezone'];
 	}
 	$local_date = gmdate($mybb->settings['dateformat'], TIME_NOW + ($timezone * 3600));
 	$local_time = gmdate($mybb->settings['timeformat'], TIME_NOW + ($timezone * 3600));
diff --git a/calendar.php b/calendar.php
index 19e5a276af..6533e1b3da 100644
--- a/calendar.php
+++ b/calendar.php
@@ -799,6 +799,7 @@
 	}
 
 	$event['name'] = htmlspecialchars_uni($event['name']);
+	$event['timezone'] = (float)$event['timezone'];
 
 	add_breadcrumb(htmlspecialchars_uni($calendar['name']), get_calendar_link($calendar['cid']));
 	add_breadcrumb($event['name'], get_event_link($event['eid']));
@@ -1536,11 +1537,11 @@
 
 	if($event['ignoretimezone'] == 0)
 	{
-		$offset = $event['timezone'];
+		$offset = (float)$event['timezone'];
 	}
 	else
 	{
-		$offset = $mybb->user['timezone'];
+		$offset = (float)$mybb->user['timezone'];
 	}
 
 	$event['starttime_user'] = $event['starttime']+$offset*3600;
@@ -1875,11 +1876,11 @@
 
 			if($event['ignoretimezone'] == 0)
 			{
-				$offset = $event['timezone'];
+				$offset = (float)$event['timezone'];
 			}
 			else
 			{
-				$offset = $mybb->user['timezone'];
+				$offset = (float)$mybb->user['timezone'];
 			}
 
 			$event['starttime_user'] = $event['starttime']+$offset*3600;
diff --git a/global.php b/global.php
index 8cb944eaa5..4c4846d2f0 100644
--- a/global.php
+++ b/global.php
@@ -924,7 +924,7 @@
 $auto_dst_detection = '';
 if($mybb->user['uid'] > 0 && $mybb->user['dstcorrection'] == 2)
 {
-	$timezone = $mybb->user['timezone'] + $mybb->user['dst'];
+	$timezone = (float)$mybb->user['timezone'] + $mybb->user['dst'];
 	eval('$auto_dst_detection = "'.$templates->get('global_dst_detection').'";');
 }
 
diff --git a/inc/datahandlers/user.php b/inc/datahandlers/user.php
index 72b4276d13..cb46c954b2 100644
--- a/inc/datahandlers/user.php
+++ b/inc/datahandlers/user.php
@@ -917,6 +917,8 @@ function verify_checkfields()
 	 */
 	function verify_timezone()
 	{
+		global $mybb;
+
 		$user = &$this->data;
 
 		$timezones = get_supported_timezones();
diff --git a/inc/functions.php b/inc/functions.php
index 5b0e09ae91..6bd3e0252b 100644
--- a/inc/functions.php
+++ b/inc/functions.php
@@ -343,17 +343,17 @@ function my_date($format, $stamp=0, $offset="", $ty=1, $adodb=false)
 	{
 		if(isset($mybb->user['uid']) && $mybb->user['uid'] != 0 && array_key_exists("timezone", $mybb->user))
 		{
-			$offset = $mybb->user['timezone'];
+			$offset = (float)$mybb->user['timezone'];
 			$dstcorrection = $mybb->user['dst'];
 		}
 		elseif(defined("IN_ADMINCP"))
 		{
-			$offset =  $mybbadmin['timezone'];
+			$offset = (float)$mybbadmin['timezone'];
 			$dstcorrection = $mybbadmin['dst'];
 		}
 		else
 		{
-			$offset = $mybb->settings['timezoneoffset'];
+			$offset = (float)$mybb->settings['timezoneoffset'];
 			$dstcorrection = $mybb->settings['dstcorrection'];
 		}
 
diff --git a/inc/functions_calendar.php b/inc/functions_calendar.php
index 99204bfc72..6f2b8bf39a 100644
--- a/inc/functions_calendar.php
+++ b/inc/functions_calendar.php
@@ -452,11 +452,11 @@ function get_events($calendar, $start, $end, $unapproved=0, $private=1)
 	{
 		if($event['ignoretimezone'] == 0)
 		{
-			$offset = $event['timezone'];
+			$offset = (float)$event['timezone'];
 		}
 		else
 		{
-			$offset = $mybb->user['timezone'];
+			$offset = (float)$mybb->user['timezone'];
 		}
 		$event['starttime_user'] = $event['starttime']+($offset*3600);
 
diff --git a/member.php b/member.php
index fac45ebb06..6bf9354014 100644
--- a/member.php
+++ b/member.php
@@ -2184,7 +2184,9 @@
 			eval("\$awaybit = \"".$templates->get("member_profile_away")."\";");
 		}
 	}
-	
+
+	$memprofile['timezone'] = (float)$memprofile['timezone'];
+
 	if($memprofile['dst'] == 1)
 	{
 		$memprofile['timezone']++;
diff --git a/modcp.php b/modcp.php
index 79f4877324..ffe8960707 100644
--- a/modcp.php
+++ b/modcp.php
@@ -1119,7 +1119,7 @@
 		$mybb->input['starttime_month'] = '01';
 	}
 
-	$localized_time_offset = $mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
+	$localized_time_offset = (float)$mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
 
 	$startdate = gmmktime((int)$startdate[0], (int)$startdate[1], 0, $mybb->get_input('starttime_month', MyBB::INPUT_INT), $mybb->get_input('starttime_day', MyBB::INPUT_INT), $mybb->get_input('starttime_year', MyBB::INPUT_INT)) -$localized_time_offset;
 	if(!checkdate($mybb->get_input('starttime_month', MyBB::INPUT_INT), $mybb->get_input('starttime_day', MyBB::INPUT_INT), $mybb->get_input('starttime_year', MyBB::INPUT_INT)) || $startdate < 0 || $startdate == false)
@@ -1261,7 +1261,7 @@
 	}
 	else
 	{
-		$localized_time = TIME_NOW + $mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
+		$localized_time = TIME_NOW + (float)$mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
 
 		$starttime_time = gmdate($mybb->settings['timeformat'], $localized_time);
 		$endtime_time = gmdate($mybb->settings['timeformat'], $localized_time);
@@ -1492,7 +1492,7 @@
 		$mybb->input['starttime_month'] = '01';
 	}
 
-	$localized_time_offset = TIME_NOW + $mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
+	$localized_time_offset = TIME_NOW + (float)$mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
 
 	$startdate = gmmktime((int)$startdate[0], (int)$startdate[1], 0, $mybb->get_input('starttime_month', MyBB::INPUT_INT), $mybb->get_input('starttime_day', MyBB::INPUT_INT), $mybb->get_input('starttime_year', MyBB::INPUT_INT)) - $localized_time_offset;
 	if(!checkdate($mybb->get_input('starttime_month', MyBB::INPUT_INT), $mybb->get_input('starttime_day', MyBB::INPUT_INT), $mybb->get_input('starttime_year', MyBB::INPUT_INT)) || $startdate < 0 || $startdate == false)
@@ -1666,8 +1666,8 @@
 	}
 	else
 	{
-		$localized_time_startdate = $announcement['startdate'] + $mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
-		$localized_time_enddate = $announcement['enddate'] + $mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
+		$localized_time_startdate = $announcement['startdate'] + (float)$mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
+		$localized_time_enddate = $announcement['enddate'] + (float)$mybb->user['timezone']*3600 + $mybb->user['dst']*3600;
 
 		$starttime_time = gmdate($mybb->settings['timeformat'], $localized_time_startdate);
 		$endtime_time = gmdate($mybb->settings['timeformat'], $localized_time_enddate);