fix date format

src/formats/DateFormat.php

@@ -12,6 +12,6 @@ class DateFormat extends BaseFormat
      */
     static function fetch(?string $data, string $options = ""): ?string
     {
-        return (new DateTimeImmutable($data))->format($options) ?? null;
+        return (new DateTimeImmutable($data ?? ""))->format($options) ?? null;
     }
 }