diff --git a/actions/profilesettings.php b/actions/profilesettings.php
index 04526a2122..cfa4db0d77 100644
--- a/actions/profilesettings.php
+++ b/actions/profilesettings.php
@@ -88,6 +88,9 @@ class ProfilesettingsAction extends SettingsAction {
 		} else if (!is_null($location) && strlen($location) > 255) {
 			$this->show_form(_('Location is too long (max 255 chars).'));
 			return;
+		}  else if (is_null($timezone) || !in_array($timezone, DateTimeZone::listIdentifiers())) {
+			$this->show_form(_('Timezone not selected.'));
+			return;
 		} else if ($this->nickname_exists($nickname)) {
 			$this->show_form(_('Nickname already in use. Try another one.'));
 			return;
@@ -99,31 +102,22 @@ class ProfilesettingsAction extends SettingsAction {
 
 		$user->query('BEGIN');
 
-		if ($user->nickname != $nickname) {
+		if ($user->nickname != $nickname ||
+			$user->language != $language ||
+			$user->timezone != $timezone) {
 
 			common_debug('Updating user nickname from ' . $user->nickname . ' to ' . $nickname,
 						 __FILE__);
+			common_debug('Updating user language from ' . $user->language . ' to ' . $language,
+						 __FILE__);
+			common_debug('Updating user timezone from ' . $user->timezone . ' to ' . $timezone,
+						 __FILE__);
 
 			$original = clone($user);
 
 			$user->nickname = $nickname;
-
-			$result = $user->updateKeys($original);
-
-			if ($result === FALSE) {
-				common_log_db_error($user, 'UPDATE', __FILE__);
-				common_server_error(_('Couldn\'t update user.'));
-				return;
-			}
-		}
-		if ($user->language != $language) {
-
-			common_debug('Updating user language from ' . $user->language . ' to ' . $language,
-						 __FILE__);
-
-			$original = clone($user);
-
 			$user->language = $language;
+			$user->timezone = $timezone;
 
 			$result = $user->updateKeys($original);
 
diff --git a/lib/common.php b/lib/common.php
index 04242432c6..b4c16660fa 100644
--- a/lib/common.php
+++ b/lib/common.php
@@ -51,7 +51,7 @@ $config =
                           'locale_path' => './locale',
                           'language' => 'en_US',
                           'languages' => get_all_languages(),
-		      'email' => 
+		      'email' =>
 		      array_key_exists('SERVER_ADMIN', $_SERVER) ? $_SERVER['SERVER_ADMIN'] : NULL,
 			  'broughtby' => NULL,
 			  'timezone' => 'UTC',
@@ -101,8 +101,9 @@ $config['db'] =
 
 require_once(INSTALLDIR.'/config.php');
 
-if (function_exists('date_default_timezone_set') && $config['site']['timezone']) {
-	date_default_timezone_set($config['site']['timezone']);
+if (function_exists('date_default_timezone_set')) {
+	/* Work internally in UTC */
+	date_default_timezone_set('UTC');
 }
 
 require_once(INSTALLDIR.'/lib/util.php');
diff --git a/lib/util.php b/lib/util.php
index 1ec68863e7..c095fe768e 100644
--- a/lib/util.php
+++ b/lib/util.php
@@ -435,6 +435,18 @@ function common_textarea($id, $label, $content=NULL, $instructions=NULL) {
 	common_element_end('p');
 }
 
+function common_timezone() {
+	if (common_logged_in()) {
+		$user = common_current_user();
+		if ($user->timezone) {
+			return $user->timezone;
+		}
+	}
+
+	global $config;
+	return $config['site']['timezone'];
+}
+
 function common_language() {
 	$httplang = isset($_SERVER['HTTP_ACCEPT_LANGUAGE']) ? $_SERVER['HTTP_ACCEPT_LANGUAGE'] : NULL;
         $language = array();
@@ -920,23 +932,31 @@ function common_date_string($dt) {
 }
 
 function common_exact_date($dt) {
-	$t = strtotime($dt);
-	return date(DATE_RFC850, $t);
+	$dateStr = date('d F Y H:i:s', strtotime($dt));
+	$d = new DateTime($dateStr, new DateTimeZone('UTC'));
+	$d->setTimezone(new DateTimeZone(common_timezone()));
+	return $d->format(DATE_RFC850);
 }
 
 function common_date_w3dtf($dt) {
-	$t = strtotime($dt);
-	return date(DATE_W3C, $t);
+	$dateStr = date('d F Y H:i:s', strtotime($dt));
+	$d = new DateTime($dateStr, new DateTimeZone('UTC'));
+	$d->setTimezone(new DateTimeZone(common_timezone()));
+	return $d->format(DATE_W3C);
 }
 
 function common_date_rfc2822($dt) {
-	$t = strtotime($dt);
-	return date("r", $t);
+	$dateStr = date('d F Y H:i:s', strtotime($dt));
+	$d = new DateTime($dateStr, new DateTimeZone('UTC'));
+	$d->setTimezone(new DateTimeZone(common_timezone()));
+	return $d->format('r');
 }
 
 function common_date_iso8601($dt) {
-	$t = strtotime($dt);
-	return date("c", $t);
+	$dateStr = date('d F Y H:i:s', strtotime($dt));
+	$d = new DateTime($dateStr, new DateTimeZone('UTC'));
+	$d->setTimezone(new DateTimeZone(common_timezone()));
+	return $d->format('c');
 }
 
 function common_redirect($url, $code=307) {