Fix typo

Author: fzaninotto

packages/ra-ui-materialui/src/input/DateInput.stories.tsx

@@ -52,7 +52,7 @@ export const DefaultValue = () => (
         browser locale
         {[
             '2021-09-11',
-            '09/11/2011', // US date format
+            '09/11/2021', // US date format
             '2021-09-11T20:46:20.000+02:00',
             '2021-09-11 20:46:20.000+02:00',
             '2021-09-11T20:46:20.000-04:00',