diff --git a/ui/src/routes/WorkingHours.svelte b/ui/src/routes/WorkingHours.svelte
index aae1de7..2757470 100644
--- a/ui/src/routes/WorkingHours.svelte
+++ b/ui/src/routes/WorkingHours.svelte
@@ -193,7 +193,7 @@
                     <div>
                         <label for="workingDay">Arbeitstag</label>
                         <input bind:value={activeRecord.workingDay} type="date"
-                               id="workingDay" required pattern="\d{4}-\d{2}-\d{2}">
+                               id="workingDay" required pattern="\d\{4}-[0-1]\d-[0-3]\d\">
                     </div>
                     <div>
                         <label for="workingTime">Arbeitszeit</label>