diff --git a/assets/images/profilePictures/user_10_69769485461a7618397775.jpg b/assets/images/profilePictures/user_10_69769485461a7618397775.jpg
new file mode 100644
index 0000000..20da055
Binary files /dev/null and b/assets/images/profilePictures/user_10_69769485461a7618397775.jpg differ
diff --git a/upload.php b/upload.php
index 1878784..ab33f56 100644
--- a/upload.php
+++ b/upload.php
@@ -106,10 +106,10 @@ if (!is_writable($targetDir))
     exit();
 }
 
-// Fallback-kompatibler Name (auch ohne random_bytes)
-$rand = uniqid('', true);
-$rand = str_replace('.', '', $rand);
-$filename = 'user_' . $userId . '_' . $rand . '.' . $ext;
+// Dateiname: user_<ID>_<Datum>.<ext>
+// Format ist dateisystem-sicher (keine Doppelpunkte) und eindeutig genug.
+$timestamp = gmdate('Ymd-His');
+$filename = 'user_' . $userId . '_' . $timestamp . '.' . $ext;
 $targetPath = rtrim($targetDir, "\\/") . DIRECTORY_SEPARATOR . $filename;
 
 if (!move_uploaded_file($tmp, $targetPath))