diff --git a/mod/item.php b/mod/item.php
index 445e2ebc22..c195ce09fc 100644
--- a/mod/item.php
+++ b/mod/item.php
@@ -284,7 +284,7 @@ function item_process(array $post, array $request, bool $preview, string $return
 	unset($post['api_source']);
 
 	if (!empty($request['scheduled_at'])) {
-		$scheduled_at = DateTimeFormat::convert($request['scheduled_at'], 'UTC', DI::app()->getTimeZone());
+		$scheduled_at = DateTimeFormat::convert($request['scheduled_at'], 'UTC', DI::apphelper()->getTimeZone());
 		if ($scheduled_at > DateTimeFormat::utcNow()) {
 			unset($post['created']);
 			unset($post['edited']);
diff --git a/src/Module/Api/Friendica/Events/Create.php b/src/Module/Api/Friendica/Events/Create.php
index 4eaad3d1ed..fdde2e9c18 100644
--- a/src/Module/Api/Friendica/Events/Create.php
+++ b/src/Module/Api/Friendica/Events/Create.php
@@ -59,11 +59,11 @@ class Create extends BaseApi
 			$finish   = DBA::NULL_DATETIME;
 			$nofinish = true;
 		} else {
-			$finish   = DateTimeFormat::convert($request['end_time'], 'UTC', DI::app()->getTimeZone());
+			$finish   = DateTimeFormat::convert($request['end_time'], 'UTC', DI::apphelper()->getTimeZone());
 			$nofinish = false;
 		}
 
-		$start = DateTimeFormat::convert($request['start_time'], 'UTC', DI::app()->getTimeZone());
+		$start = DateTimeFormat::convert($request['start_time'], 'UTC', DI::apphelper()->getTimeZone());
 
 		// create event
 		$event = [];
diff --git a/src/Module/Settings/Account.php b/src/Module/Settings/Account.php
index 8e8bd5a909..6c8a473470 100644
--- a/src/Module/Settings/Account.php
+++ b/src/Module/Settings/Account.php
@@ -40,8 +40,6 @@ class Account extends BaseSettings
 
 		self::checkFormSecurityTokenRedirectOnError($redirectUrl, 'settings');
 
-		$a = DI::app();
-
 		$user = User::getById($this->session->getLocalUserId());
 
 		if (!empty($request['password-submit'])) {
@@ -111,7 +109,7 @@ class Account extends BaseSettings
 			}
 
 			if (strlen($timezone) && $timezone != $user['timezone']) {
-				$a->setTimeZone($timezone);
+				DI::apphelper()->setTimeZone($timezone);
 			}
 
 			$fields = [
@@ -383,8 +381,6 @@ class Account extends BaseSettings
 			return '';
 		}
 
-		$a = DI::app();
-
 		$user = User::getById($this->session->getLocalUserId());
 
 		$username         = $user['username'];
@@ -404,7 +400,7 @@ class Account extends BaseSettings
 		$expire_network_only = DI::pConfig()->get(DI::userSession()->getLocalUserId(), 'expire', 'network_only', false);
 
 		if (!strlen($user['timezone'])) {
-			$timezone = $a->getTimeZone();
+			$timezone = DI::apphelper()->getTimeZone();
 		}
 
 		// Set the account type to "Community" when the page is a community page but the account type doesn't fit
diff --git a/src/Protocol/Feed.php b/src/Protocol/Feed.php
index 999f88febc..9800fd2433 100644
--- a/src/Protocol/Feed.php
+++ b/src/Protocol/Feed.php
@@ -556,7 +556,7 @@ class Feed
 				Logger::info('Feed is too old', ['created' => $item['created'], 'uid' => $item['uid'], 'uri' => $item['uri']]);
 				continue;
 			}
-			
+
 			if (!empty($item['plink'])) {
 				$fetch_further_information = $contact['fetch_further_information'] ?? LocalRelationship::FFI_NONE;
 			} else {
@@ -1014,7 +1014,7 @@ class Feed
 
 		// Display events in the user's timezone
 		if (strlen($owner['timezone'])) {
-			DI::app()->setTimeZone($owner['timezone']);
+			DI::apphelper()->setTimeZone($owner['timezone']);
 		}
 
 		$previous_created = $last_update;
diff --git a/src/Util/Temporal.php b/src/Util/Temporal.php
index d3ed346908..64ab47b98c 100644
--- a/src/Util/Temporal.php
+++ b/src/Util/Temporal.php
@@ -264,7 +264,7 @@ class Temporal
 				$input_text,
 				DI::l10n()->t(
 					'Time zone: <strong>%s</strong> <a href="%s">Change in Settings</a>',
-					str_replace('_', ' ', DI::app()->getTimeZone()) . ' (GMT ' . DateTimeFormat::localNow('P') . ')',
+					str_replace('_', ' ', DI::apphelper()->getTimeZone()) . ' (GMT ' . DateTimeFormat::localNow('P') . ')',
 					DI::baseUrl() . '/settings'
 				),
 				$required ? '*' : '',