diff --git a/components/ideas/idea-timeline.tsx b/components/ideas/idea-timeline.tsx
index 81a506b..133e176 100644
--- a/components/ideas/idea-timeline.tsx
+++ b/components/ideas/idea-timeline.tsx
@@ -100,7 +100,12 @@ export function IdeaTimeline({ logs, questions }: Props) {
   return (
     <ol className="border-l-2 border-input pl-4 space-y-3 ml-2">
       {merged.map((entry, i) => {
-        const time = new Date(entry.created_at).toLocaleString()
+        // Expliciete locale + format om SSR/CSR hydration-mismatch te voorkomen
+        // (server-locale verschilde van browser-locale).
+        const time = new Date(entry.created_at).toLocaleString('nl-NL', {
+          dateStyle: 'short',
+          timeStyle: 'short',
+        })
 
         if (entry.kind === 'log') {
           const type = entry.data.type as IdeaLogType