diff --git a/library/src/calculate_price.cpp b/library/src/calculate_price.cpp
index f4e586f..002b091 100644
--- a/library/src/calculate_price.cpp
+++ b/library/src/calculate_price.cpp
@@ -148,6 +148,14 @@ CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
     double minMin = tariff->PaymentOption.find(PaymentOption::Option1)->second.pop_min_time;
     double maxMin = tariff->PaymentOption.find(PaymentOption::Option1)->second.pop_max_time;
 
+    // DEBUG
+    qCritical() << "compute_price_for_parking_ticket() " << endl
+                << "          start_parking_time: " << start_parking_time << endl
+                << "            end_parking_time: " << end_parking_time   << endl
+                << "                      minMin: " << minMin << endl
+                << "                      maxMin: " << maxMin;
+
+
     int const duration = (end_parking_time.toSecsSinceEpoch() -
                           start_parking_time.toMSecsSinceEpoch()) / 60;
 
@@ -181,6 +189,10 @@ CalcState CALCULATE_LIBRARY_API compute_price_for_parking_ticket(
             calcState.setDesc(QString("minCost=%1, cost=%2").arg(minCost, cost));
             return calcState.set(CalcState::State::BELOW_MIN_PARKING_PRICE);
         }
+
+        // DEBUG
+        qCritical() << "               -> calculated cost (price->netto) =  " << cost;
+
         price->units = cost;
         price->netto = cost;
     } else {
@@ -202,6 +214,12 @@ CalcState CALCULATE_LIBRARY_API compute_duration_for_parking_ticket(
     start = start.toLocalTime().addSecs(start_parking_time * 60);
     if (start.isValid()) {
         QString cs = start.toString(Qt::ISODate);
+
+        // DEBUG
+        qCritical() << "compute_duration_for_parking_ticket(): ";
+        qCritical() << "      start (cs): " << cs;
+        qCritical() << "           price: " << price;
+
         duration = calculator.GetDurationFromCost(tariff, PaymentOption::Option1,
                                                   cs.toLocal8Bit().constData(),
                                                   price, false, true).c_str();
@@ -230,6 +248,12 @@ CalcState CALCULATE_LIBRARY_API compute_duration_for_parking_ticket(
                                         cs.toLocal8Bit().constData(),
                                         price, false, true).c_str();
         ticketEndTime = QDateTime::fromString(endTime);
+
+        // DEBUG
+        qCritical() << "compute_duration_for_parking_ticket(): ";
+        qCritical() << "                 endTime: " << endTime;
+        qCritical() << "           ticketEndTime: " << ticketEndTime;
+
         if (!ticketEndTime.isValid()) {
             calcState.setDesc(QString("ticketEndTime=%1").arg(endTime));
             return calcState.set(CalcState::State::WRONG_ISO_TIME_FORMAT);