diff --git a/public/index.php b/public/index.php
index 26b639b..d1002a8 100644
--- a/public/index.php
+++ b/public/index.php
@@ -95,17 +95,17 @@ if (!isset($_SESSION['user_id']) && isset($_COOKIE['remember_token']) && !$isIns
 }
 
 // Set application timezone early (before any date operations)
-if (!$isInstallerPath && file_exists($installedFlagFile)) {
+// Also apply on installer paths (e.g. /install/update) when the app is already installed,
+// so that notifications created during upgrades use the correct timezone.
+if (file_exists($installedFlagFile)) {
     try {
         $settingModel = new \App\Models\Setting();
         $timezone = $settingModel->getValue('app_timezone', 'UTC');
         date_default_timezone_set($timezone);
     } catch (\Exception $e) {
-        // Database not available, use UTC as fallback
         date_default_timezone_set('UTC');
     }
 } else {
-    // Default to UTC during installation
     date_default_timezone_set('UTC');
 }