diff --git a/Abrechnung/module.php b/Abrechnung/module.php
index 5678267..8cbb939 100644
--- a/Abrechnung/module.php
+++ b/Abrechnung/module.php
@@ -231,55 +231,98 @@ private function AddMeterToPDFRow($meter, $tariffs, $from, $to, $type)
 {
     $startVal = $this->GetValueAt($meter['var_consumption'], $from);
     $endVal   = $this->GetValueAt($meter['var_consumption'], $to);
-    if ($startVal === null || $endVal === null) return ['row' => '', 'value' => 0];
+    if ($startVal === null || $endVal === null) {
+        IPS_LogMessage('Abrechnung', "❌ Kein Wert für {$meter['name']} ($type)");
+        return ['row' => '', 'value' => 0];
+    }
 
     $totalDiff = max(0, $endVal - $startVal);
-    if ($totalDiff <= 0) return ['row' => '', 'value' => 0];
+    if ($totalDiff <= 0) {
+        IPS_LogMessage('Abrechnung', "⚠️ Kein Verbrauch für {$meter['name']} ($type): Start=$startVal, Ende=$endVal");
+        return ['row' => '', 'value' => 0];
+    }
+
+    IPS_LogMessage('Abrechnung', "📊 {$meter['name']} ($type): Verbrauch gesamt=$totalDiff");
 
     $rows = '';
     $totalCost = 0.0;
+    $foundTariff = false;
 
-    // Alle Tarife dieses Typs prüfen
-        foreach ($tariffs as $t) {
-            if (strtolower($t['unit_type']) != strtolower($type)) continue;
+    foreach ($tariffs as $t) {
+        if (!isset($t['start'], $t['end'], $t['price'], $t['unit_type'])) continue;
+        if (strtolower($t['unit_type']) != strtolower($type)) continue;
 
-            $tariffStart = strtotime($t['start']);
-            $tariffEnd   = strtotime($t['end']);
+        $tariffStart = strtotime($t['start']);
+        $tariffEnd   = strtotime($t['end']);
+        if ($tariffEnd < $from || $tariffStart > $to) continue;
 
-            // Zeitliche Überschneidung mit Abrechnungszeitraum?
-            if ($tariffEnd < $from || $tariffStart > $to) continue;
+        $foundTariff = true;
 
-            // Überschneidung bestimmen
-            $sectionStart = max($from, $tariffStart);
-            $sectionEnd   = min($to, $tariffEnd);
-            $sectionDuration = $sectionEnd - $sectionStart;
-            $totalDuration   = $to - $from;
+        $sectionStart = max($from, $tariffStart);
+        $sectionEnd   = min($to, $tariffEnd);
+        $sectionDuration = $sectionEnd - $sectionStart;
+        $totalDuration   = $to - $from;
 
-            if ($sectionDuration <= 0) continue;
+        if ($sectionDuration <= 0) continue;
 
-            // Anteil des Gesamtverbrauchs nach Zeitanteil
-            $sectionFraction = $sectionDuration / $totalDuration;
-            $sectionDiff = $totalDiff * $sectionFraction;
+        $sectionFraction = $sectionDuration / $totalDuration;
+        $sectionDiff = $totalDiff * $sectionFraction;
 
-            $tariffRp = floatval($t['price']);
-            $costCHF  = ($tariffRp / 100) * $sectionDiff;
+        $tariffRp = floatval($t['price']);
+        $costCHF  = ($tariffRp / 100) * $sectionDiff;
 
-            $rows .= "
-            <tr>
-                <td>{$meter['name']}</td>
-                <td>$type</td>
-                <td>" . date('d.m.Y', $sectionStart) . "</td>
-                <td>" . date('d.m.Y', $sectionEnd) . "</td>
-                <td>" . number_format($sectionDiff, 2) . "</td>
-                <td>" . number_format($tariffRp, 2) . "</td>
-                <td>" . number_format($costCHF, 2) . "</td>
-            </tr>";
+        IPS_LogMessage('Abrechnung', "→ Tarif {$t['price']} Rp vom " . date('d.m.Y', $tariffStart) . " bis " . date('d.m.Y', $tariffEnd) . 
+            " deckt " . date('d.m.Y', $sectionStart) . "–" . date('d.m.Y', $sectionEnd) . " ab, Anteil=" . round($sectionFraction*100,1) . "%");
 
-            $totalCost += $costCHF;
-        }
+        $rows .= "
+        <tr>
+            <td>{$meter['name']}</td>
+            <td>$type</td>
+            <td>" . date('d.m.Y', $sectionStart) . "</td>
+            <td>" . date('d.m.Y', $sectionEnd) . "</td>
+            <td>" . number_format($sectionDiff, 2) . "</td>
+            <td>" . number_format($tariffRp, 2) . "</td>
+            <td>" . number_format($costCHF, 2) . "</td>
+        </tr>";
 
-        return ['row' => $rows, 'value' => $totalCost];
+        $totalCost += $costCHF;
     }
 
+    if (!$foundTariff) {
+        IPS_LogMessage('Abrechnung', "⚠️ Kein Tarif für $type im Zeitraum gefunden");
+    }
+
+    return ['row' => $rows, 'value' => $totalCost];
+}
+
+    private function GetValueAt(int $varId, int $timestamp)
+    {
+        $archiveID = @IPS_GetInstanceListByModuleID('{43192F0B-135B-4CE7-A0A7-1475603F3060}')[0];
+        if (!$archiveID || !IPS_VariableExists($varId)) {
+            IPS_LogMessage('Abrechnung', "⚠️ Archiv oder Variable fehlt für ID $varId");
+            return null;
+        }
+
+        // Letzter Wert vor oder gleich Timestamp
+        $before = @AC_GetLoggedValues($archiveID, $varId, $timestamp - 86400 * 60, $timestamp, 1);
+        if ($before && count($before) > 0) {
+            $val = floatval($before[0]['Value']);
+            IPS_LogMessage('Abrechnung', "📉 Wert vor $timestamp: $val");
+            return $val;
+        }
+
+        // Erster Wert nach Timestamp
+        $after = @AC_GetLoggedValues($archiveID, $varId, $timestamp, $timestamp + 86400 * 60, 1);
+        if ($after && count($after) > 0) {
+            $val = floatval($after[0]['Value']);
+            IPS_LogMessage('Abrechnung', "📈 Wert nach $timestamp: $val");
+            return $val;
+        }
+
+        // Fallback auf aktuellen Wert
+        $val = floatval(GetValue($varId));
+        IPS_LogMessage('Abrechnung', "⚙️ Fallback Wert (aktuell): $val");
+        return $val;
+    }
 
 }
\ No newline at end of file