diff --git a/library/src/calculate_price.cpp b/library/src/calculate_price.cpp
index 531d326..01275e1 100644
--- a/library/src/calculate_price.cpp
+++ b/library/src/calculate_price.cpp
@@ -885,6 +885,9 @@ CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
                 }
             }
 
+            effectiveStartTime.setTime(QTime(effectiveStartTime.time().hour(),
+                                             effectiveStartTime.time().minute(), 0));
+
             qCritical() << __func__ << ":" << __LINE__ << "effectiveStartTime:" << effectiveStartTime.toString(Qt::ISODate);
 
             int const carryOver = tariff->getPaymentOptions(paymentOptionIndex).pop_carry_over;
@@ -950,6 +953,8 @@ CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
                     //QTime const &tlimit = wd.getTariffCarryOverSettings().parkingTimeLimit();
                     //end_parking_time.setTime(tlimit);
 
+                    // max_price neu berechnen
+
                     calcState.setDesc(QString("line=%1 endTime=%2: park-time-limit violated").arg(__LINE__)
                                         .arg(end_parking_time.time().toString(Qt::ISODate)));
                     return calcState.set(CalcState::State::ABOVE_MAX_PARKING_TIME);
@@ -1086,6 +1091,10 @@ CalcState CALCULATE_LIBRARY_API compute_duration_for_parking_ticket(
         if (pop_time_step_config == (int)ATBTimeStepConfig::TimeStepConfig::STATIC) {
             // handle prepaid option
             QDateTime effectiveStartTime(start_parking_time);
+
+            effectiveStartTime.setTime(QTime(effectiveStartTime.time().hour(),
+                                             effectiveStartTime.time().minute(), 0));
+
             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()) {
@@ -1102,8 +1111,9 @@ CalcState CALCULATE_LIBRARY_API compute_duration_for_parking_ticket(
                 }
             }
         }
-
-        QString cs = start_parking_time.toString(Qt::ISODate);
+        QDateTime start(start_parking_time);
+        start.setTime(QTime(start.time().hour(), start.time().minute(), 0));
+        QString cs = start.toString(Qt::ISODate);
 
         std::pair<std::string, QDateTime> p_endTime
                 = Calculator::GetInstance().GetDurationFromCost(
@@ -1181,8 +1191,14 @@ CalcState CALCULATE_LIBRARY_API compute_duration_for_parking_ticket(
         } else {
             ticketEndTime = QDateTime::fromString(endTime,Qt::ISODate);
 
+            ticketEndTime.setTime(QTime(ticketEndTime.time().hour(),
+                                        ticketEndTime.time().minute(), 0));
+
+            int netto_parking_time = start_parking_time.secsTo(ticketEndTime) / 60;
+
             qCritical() << __func__ << ":" << __LINE__ << "ticketEndTime:" << ticketEndTime.toString(Qt::ISODate);
             qCritical() << __func__ << ":" << __LINE__ << "step-config:" << pop_time_step_config;
+            qCritical() << __func__ << ":" << __LINE__ << "netto-parking-time" << netto_parking_time;
 
             if (!ticketEndTime.isValid()) {
                 calcState.setDesc(QString("ticketEndTime=%1").arg(endTime));