diff --git a/library/include/mobilisis/configuration.h b/library/include/mobilisis/configuration.h
index 44de256..610ac58 100644
--- a/library/include/mobilisis/configuration.h
+++ b/library/include/mobilisis/configuration.h
@@ -36,6 +36,9 @@ class Calculator;
 class Configuration
 {
 public:
+    using SpecialDaysType = std::multimap<int, ATBSpecialDays>;
+    using SpecialDaysWorktimeType = std::multimap<int, ATBSpecialDaysWorktime>;
+
     ATBProject project;
     ATBCurrency Currency;
 	ATBDuration duration;
@@ -43,8 +46,8 @@ public:
 	multimap<int, ATBDuration> Duration;
 	multimap<int, ATBPaymentMethod> PaymentMethod;
 	multimap<int, ATBPaymentRate> PaymentRate;
-	multimap<int, ATBSpecialDaysWorktime> SpecialDaysWorktime;
-	multimap<int, ATBSpecialDays> SpecialDays;
+    SpecialDaysWorktimeType SpecialDaysWorktime;
+    SpecialDaysType SpecialDays;
 	multimap<int, ATBWeekDays> WeekDays;
 	multimap<int, ATBPeriodYear> YearPeriod;
 	multimap<int, ATBWeekDaysWorktime> WeekDaysWorktime;
@@ -67,8 +70,14 @@ public:
     ATBPaymentOption const &getPaymentOptions(int paymentOptionsIndex=0) const;
     QVector<ATBPaymentOption> &getAllPaymentOptions();
     QVector<ATBPaymentOption> const &getAllPaymentOptions() const;
-    int getCurrentPaymentOptionIndex(QDateTime const &dt) const;
-    bool isHoliday(QDateTime const &dt) const;
+    int getPaymentOptionIndex(QDateTime const &dt) const;
+    int getPaymentOptionIndexIfSpecialDay(QDateTime const &dt) const;
+    bool isSpecialDay(QDateTime const &dt) const;
+    int specialDayId(QDateTime const &dt) const;
+    ATBSpecialDays specialDay(QDateTime const &dt) const;
+    bool isDayIncluded(uint64_t businessHours, QDateTime const &dt) const;
+    bool isDayIncludedAsSpecialDay(uint64_t businessHours, QDateTime const &dt) const;
+    bool isDayIncludedAsSpecialDay(uint64_t businessHours, int specialDayId) const;
     std::optional<QVector<ATBPaymentRate>> getPaymentRateForAllKeys() const;
     std::optional<QVector<ATBPaymentRate>> getPaymentRateForKey(int key) const;
     std::optional<QVector<ATBDailyTicket>> getDailyTicketsForAllKeys() const;