diff --git a/srv/poe_manager/templates/index.html b/srv/poe_manager/templates/index.html
index 1f839b5..b3e19c3 100644
--- a/srv/poe_manager/templates/index.html
+++ b/srv/poe_manager/templates/index.html
@@ -46,10 +46,15 @@ document.addEventListener("DOMContentLoaded", () => {
     function updateTimer() {
         const now = Date.now();
         const elapsed = now - lastUpdateTime;
-        const remainingMs = intervalMilliseconds - (elapsed % intervalMilliseconds);
-        const remainingSec = Math.ceil(remainingMs / 1000);
+        const remainingMs = intervalMilliseconds - elapsed;
+        const remainingSec = Math.ceil(Math.max(remainingMs, 0) / 1000);
         document.getElementById("dashboard-timer").innerText =
             `Nächste Prüfung in ${remainingSec} Sekunden`;
+
+        if (elapsed >= intervalMilliseconds) {
+            // Timer abgelaufen → Reload starten
+            window.location.reload();
+        }
     }
 
     function fetchLastLog() {