diff --git a/server/set-all-birthday-visible.mjs b/server/set-all-birthday-visible.mjs
new file mode 100644
index 0000000..f07ac9f
--- /dev/null
+++ b/server/set-all-birthday-visible.mjs
@@ -0,0 +1,33 @@
+// Script: set-all-birthday-visible.mjs
+// Setzt für alle Mitglieder das Flag visibility.showBirthday auf true (mit Entschlüsselung)
+
+import { readMembers, writeMembers } from './utils/members.js';
+import dotenv from 'dotenv';
+import path from 'path';
+import { fileURLToPath } from 'url';
+
+dotenv.config({ path: path.resolve(process.cwd(), '.env') });
+
+async function main() {
+  let members = await readMembers();
+  if (!Array.isArray(members)) {
+    console.error('members.json ist kein Array!')
+    process.exit(1)
+  }
+  let changed = 0;
+  for (const m of members) {
+    if (!m.visibility) m.visibility = {};
+    if (m.visibility.showBirthday !== true) {
+      m.visibility.showBirthday = true;
+      changed++;
+    }
+  }
+  if (changed > 0) {
+    await writeMembers(members);
+    console.log(`Flag für ${changed} Mitglieder gesetzt.`);
+  } else {
+    console.log('Alle Mitglieder hatten das Flag bereits gesetzt.');
+  }
+}
+
+main();