diff --git a/library/src/calculate_price.cpp b/library/src/calculate_price.cpp
index 7d76560..6aca26e 100644
--- a/library/src/calculate_price.cpp
+++ b/library/src/calculate_price.cpp
@@ -708,7 +708,7 @@ CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
 
 CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
         parking_tariff_t *tariff,
-        QDateTime &start_parking_time,
+        QDateTime &start_parking_time_,
         int netto_parking_time,
         QDateTime &end_parking_time,
         struct price_t *price,
@@ -717,6 +717,8 @@ CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
 {
     CalcState calcState;
 
+    QDateTime start_parking_time(start_parking_time_);
+
     int paymentOptionIndex = tariff->getPaymentOptionIndex(permitType);
 
     double minMin = tariff->getPaymentOptions(paymentOptionIndex).pop_min_time;
@@ -730,9 +732,9 @@ CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
                 << "               start + netto: " << start_parking_time.addSecs(netto_parking_time * 60) << endl
                 << "                      minMin: " << minMin << endl
                 << "                      maxMin: " << maxMin
+                << "                     prepaid: " << prepaid
                 << "                  permitType: " << permitType.toString();
 
-
     if (netto_parking_time < 0) {
         calcState.setDesc(QString("end=%1, start=%2")
                           .arg(end_parking_time.toString(Qt::ISODate),
@@ -753,59 +755,65 @@ CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
 
     double cost = -1;
     if (start_parking_time.isValid()) {
-
-        // qCritical() << __func__ << __LINE__;
-
         if (tariff->getPaymentOptions(paymentOptionIndex).pop_payment_method_id == PaymentMethod::Steps ||
             tariff->getPaymentOptions(paymentOptionIndex).pop_payment_method_id == PaymentMethod::Degressive) {
-        // qCritical() << __func__ << __LINE__;
             // hier muesste man unterscheiden: uebertrag oder nicht?
             calcState = Calculator::GetInstance().isParkingAllowed(tariff, start_parking_time,
                                                                    netto_parking_time, paymentOptionIndex);
             if (calcState.getStatus() == CalcState::State::OUTSIDE_ALLOWED_PARKING_TIME) {
-                 qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
-                             << calcState.toString();
-        // qCritical() << __func__ << __LINE__;
+                qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
+                            << calcState.toString();
                 return calcState;
             }
-        // qCritical() << __func__ << __LINE__;
 
-            QList<int> lll = Calculator::GetInstance().GetTimeSteps(tariff);
+            QList<int> tlist = Calculator::GetInstance().GetTimeSteps(tariff);
+            Q_UNUSED(tlist);
 
-            // netto_parking_time = compute_next_timestep(tariff, netto_parking_time, 1, permitType);
-
-            qCritical() << "LINE" << __LINE__ << "netto" << netto_parking_time << lll;
-
-        // qCritical() << __func__ << __LINE__;
             cost = Calculator::GetInstance().GetCostFromDuration(tariff, start_parking_time, netto_parking_time, paymentOptionIndex);
 
             int weekDay = start_parking_time.date().dayOfWeek();
-            int const pop_carry_over_option_id = tariff->getPaymentOptions(paymentOptionIndex).pop_carry_over_option_id;
+            int pop_carry_over_option_id = tariff->getPaymentOptions(paymentOptionIndex).pop_carry_over_option_id;
+
+            std::optional<ATBPeriodYear> yperiod = Utilities::GetYearPeriodActive(tariff, start_parking_time);
+            if (yperiod.has_value()) {
+                ATBPeriodYear const &period = yperiod.value();
+                pop_carry_over_option_id = period.pye_id;
+            }
+            qCritical() << __func__ << __LINE__ << "carryOver-id" << pop_carry_over_option_id;
+
             QTime const carryOverStart = tariff->TariffCarryOverOptions.find(pop_carry_over_option_id)->second.carryover[weekDay].static_start;
-            //QTime const carryOverEnd = cfg->TariffCarryOverOptions.find(pop_carry_over_option_id)->second.carryover[weekDay].static_end;
             int const carryOverDuration = tariff->TariffCarryOverOptions.find(pop_carry_over_option_id)->second.carryover[weekDay].duration;
 
-            qCritical() << "LINE" << __LINE__ << "carryStart" << carryOverStart.toString(Qt::ISODate);
-            qCritical() << "LINE" << __LINE__ << "carryDur" << carryOverDuration;
-            qCritical() << "LINE" << __LINE__ << "start" << start_parking_time.toString(Qt::ISODate);
+            qCritical() << __func__ << __LINE__ << "carryOverStart" << carryOverStart.toString(Qt::ISODate);
+            qCritical() << __func__ << __LINE__ << "carryOverDuration" << carryOverDuration;
 
-            if (start_parking_time.time() > carryOverStart) {
-                //int const backTime = carryOverStart.secsTo(start_parking_time.time()) / 60;
-            //qCritical() << "LINE" << __LINE__ << "backTime" << backTime;
-            //qCritical() << "LINE" << __LINE__ << "backTime + dur" << backTime + carryOverDuration;
-                start_parking_time.setTime(carryOverStart);
-                start_parking_time = start_parking_time.addSecs(carryOverDuration * 60);
+            // handle prepaid option
+            QDateTime effectiveStartTime(start_parking_time);
+            int const prepaid_option_id = tariff->getPaymentOptions(paymentOptionIndex).pop_prepaid_option_id;
+            std::optional<ATBPrepaid> prepaidOption = tariff->getPrepaidType(prepaid_option_id);
+            if (prepaidOption.has_value()) {
+                ATBPrepaid const &p = prepaidOption.value();
+                if (start_parking_time.time() < p.static_end) {     // static_end: e.g. 08:00:00
+                    effectiveStartTime.setTime(p.static_end);
+                } else
+                if (start_parking_time.time() > p.static_start) {   // static_start: e.g. 22:00:00
+                    effectiveStartTime.setTime(p.static_start);
+                }
             }
 
-            end_parking_time = start_parking_time.addSecs(netto_parking_time*60);
-
-            qCritical() << "LINE" << __LINE__ << "netto" << netto_parking_time;
-            qCritical() << "LINE" << __LINE__ << "start" << start_parking_time.toString(Qt::ISODate);
-            qCritical() << "(" << __func__ << ":" << __LINE__ << ")"
-                         << "end_parking_time" << end_parking_time.toString(Qt::ISODate);
+            // handle carry over
+            int minutesUntilCarryOver = effectiveStartTime.time().secsTo(carryOverStart) / 60;
+            if (netto_parking_time > minutesUntilCarryOver) {
+                int const rest = netto_parking_time - minutesUntilCarryOver;
+                QDateTime s(effectiveStartTime);
+                s = s.addSecs(minutesUntilCarryOver * 60);
+                s = s.addSecs(carryOverDuration * 60);
+                end_parking_time = s.addSecs(rest * 60);
+            } else {
+                end_parking_time = effectiveStartTime.addSecs(netto_parking_time*60);
+            }
 
         } else {
-        // qCritical() << __func__ << __LINE__;
             cost = Calculator::GetInstance().GetCostFromDuration(
                         tariff,
                         tariff->getPaymentOptions().pop_payment_method_id,
@@ -822,8 +830,8 @@ CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
         }
 
         // DEBUG
-        qCritical() << __LINE__ << "            end_parking_time: " << end_parking_time;
-        qCritical() << __LINE__ << "  -> calculated cost (netto): " << cost;
+        //qCritical() << __LINE__ << "            end_parking_time: " << end_parking_time;
+        //qCritical() << __LINE__ << "  -> calculated cost (netto): " << cost;
 
         price->brutto = price->vat = price->vat_percentage = 0;
         price->units = cost;
@@ -899,10 +907,12 @@ CalcState CALCULATE_LIBRARY_API compute_duration_for_parking_ticket(
     bool const nextDay = false;
 
     // DEBUG
-    qCritical() << "compute_duration_for_parking_ticket(2): ";
-    qCritical() << " payment option index: " << paymentOptionIndex;
-    qCritical() << "              prepaid: " << prepaid;
-    qCritical() << "                price: " << price;
+    if (DBG_LEVEL >= DBG_DEBUG) {
+        qCritical() << "compute_duration_for_parking_ticket(2): ";
+        qCritical() << " payment option index: " << paymentOptionIndex;
+        qCritical() << "              prepaid: " << prepaid;
+        qCritical() << "                price: " << price;
+    }
 
     if (start_parking_time.isValid()) {
         QString cs = start_parking_time.toString(Qt::ISODate);