diff --git a/Web/templates/termin_configure.html b/Web/templates/termin_configure.html
index 7765f4f..699c1c4 100644
--- a/Web/templates/termin_configure.html
+++ b/Web/templates/termin_configure.html
@@ -202,7 +202,19 @@
         if (slotsAmountsInput) slotsAmountsInput.value = totalSlots;
         if (slotsAmountsDisplay) slotsAmountsDisplay.innerText = totalSlots + " Slots gesamt";
     }
-
+    
+    // Helper utility in case your timeToMinutes handler doesn't catch empty strings safely
+    function safeTimeToMinutes(timeString) {
+        if (!timeString || typeof timeString !== 'string' || !timeString.includes(':')) {
+            return 0; // Return 0 instead of NaN for empty or missing values
+        }
+        const parts = timeString.split(':');
+        const hours = parseInt(parts[0], 10);
+        const minutes = parseInt(parts[1], 10);
+        if (isNaN(hours) || isNaN(minutes)) return 0;
+        return (hours * 60) + minutes;
+    }
+    
     // Berechnet die Slots basierend auf den konfigurierten Zeiten & Pausen
     function calculateSlots() {
         if (!slotLengthInput || !slotsAmountsInput || !clientsperslot) return;
@@ -212,25 +224,29 @@
             updateSlotsDisplay(0);
             return;
         }
-
+    
+        // FIX 1: Make sure we parse the input VALUE, defaulting to 1 if empty or invalid
+        const multiplier = parseInt(clientsperslot.value, 10) || 1;
+    
         let totalSlots = 0;
         const rows = Array.from(daysContainer.querySelectorAll('[data-day-row]'));
-
+    
         rows.forEach(row => {
             const startTime = row.querySelector('[data-time-start]')?.value;
             const endTime = row.querySelector('[data-time-end]')?.value;
             const pauseStart = row.querySelector('[data-time-pause-start]')?.value;
             const pauseEnd = row.querySelector('[data-time-pause-end]')?.value;
-
+        
             if (!startTime || !endTime) return;
-
-            const startMins = timeToMinutes(startTime);
-            const endMins = timeToMinutes(endTime);
-            const pauseStartMins = timeToMinutes(pauseStart);
-            const pauseEndMins = timeToMinutes(pauseEnd);
-
-            if (endMins <= startMins) return; // Ungültige Zeit
-
+        
+            // Using safety parsing to prevent missing values from generating NaN
+            const startMins = safeTimeToMinutes(startTime);
+            const endMins = safeTimeToMinutes(endTime);
+            const pauseStartMins = safeTimeToMinutes(pauseStart);
+            const pauseEndMins = safeTimeToMinutes(pauseEnd);
+        
+            if (isNaN(startMins) || isNaN(endMins) || endMins <= startMins) return;
+        
             // Wenn eine gültige Pause innerhalb der Start/Endzeit existiert
             if (pauseStartMins > 0 && pauseEndMins > 0 && pauseStartMins < pauseEndMins && pauseStartMins > startMins && pauseStartMins < endMins) {
                 // Segment 1 (Vor der Pause)
@@ -248,8 +264,12 @@
                 totalSlots += Math.floor((endMins - startMins) / slotLength);
             }
         });
-        totalSlotscomplete = totalSlots * Number(clientsperslot)
-        updateSlotsDisplay(totalSlotscomplete);
+    
+        // FIX 2: Multiply by our safely parsed input value scalar
+        const totalSlotscomplete = totalSlots * multiplier;
+        
+        // Safety check: if anything went wrong anyway, fallback to 0 instead of displaying NaN
+        updateSlotsDisplay(isNaN(totalSlotscomplete) ? 0 : totalSlotscomplete);
     }
 
     // Synchronisiert das Textfeld und fügt den Break-Cut hinzu