diff --git a/library/include/mobilisis/calculator_functions.h b/library/include/mobilisis/calculator_functions.h
index bad0566..f757d76 100644
--- a/library/include/mobilisis/calculator_functions.h
+++ b/library/include/mobilisis/calculator_functions.h
@@ -1,7 +1,14 @@
-#pragma once
+#ifndef CALCULATOR_FUNCTIONS_H_INCLUDED
+#define CALCULATOR_FUNCTIONS_H_INCLUDED
+
 #include <iostream>
+#include <optional>
+
 #include "configuration.h"
 #include "payment_method.h"
+#include "ticket.h"
+#include "tariff_time_range.h"
+
 #include <QDateTime>
 using namespace std;
 
@@ -49,13 +56,13 @@ private:
     int getMinimalParkingTime(Configuration const *cfg, PaymentMethod methodId);
     int getMaximalParkingTime(Configuration const *cfg, PaymentMethod methodId);
 
-    uint32_t private_GetCostFromDuration(Configuration const* cfg,
-                                         QDateTime const &start,
-                                         QDateTime &end,
-                                         int durationMinutes,
-                                         bool nextDay = false,
-                                         bool prepaid = false,
-                                         bool overtime = false);
+    Ticket private_GetCostFromDuration(Configuration const* cfg,
+                                       QDateTime const &start,
+                                       QDateTime &end,
+                                       int &durationMinutes,
+                                       bool nextDay = false,
+                                       bool prepaid = false,
+                                       bool overtime = false);
 
     bool checkDurationMinutes(bool overTime,
                               int minParkingTime, int maxParkingTime,
@@ -64,4 +71,13 @@ private:
     //
     uint32_t GetPriceForTimeStep(Configuration *cfg, int timeStep) const;
     uint32_t GetDurationForPrice(Configuration *cfg, int price) const;
+
+    int findWorkTimeRange(QDateTime const &dt,
+                          QScopedArrayPointer<TariffTimeRange> const &worktime,
+                          size_t size);
+    int findNextWorkTimeRange(QDateTime const &dt,
+                              QScopedArrayPointer<TariffTimeRange> const &worktime,
+                              size_t size);
 };
+
+#endif // CALCULATOR_FUNCTIONS_H_INCLUDED