diff --git a/src/game/Calendar.h b/src/game/Calendar.h
index 10b75b5..3f3b33b 100644
--- a/src/game/Calendar.h
+++ b/src/game/Calendar.h
@@ -19,8 +19,86 @@
 #ifndef MANGOS_CALENDAR_H
 #define MANGOS_CALENDAR_H

+#include "Common.h"
+#include "ObjectGuid.h"
+#include "Policies/Singleton.h"
+#include <ace/RW_Thread_Mutex.h>
+
+struct CalendarEventInvite
+{
+    std::string m_Name;
+    ObjectGuid  m_eventGuid;
+    ObjectGuid  m_inviterGuid;
+    ObjectGuid  m_playerGuid;
+    uint8       unk12;
+    uint8       unk13;
+};
+
+typedef std::set<CalendarEventInvite*> EventInvitesList;
+
+struct CalendarEvent
+{
+    ObjectGuid       m_guid;
+    ObjectGuid       m_creatorGuid;
+    std::string      m_eventName;
+    std::string      m_eventDescription;
+    uint8            m_eventType;
+    uint8            unk4;
+    uint32           unk5;
+    uint32           m_instance;
+    uint32           m_time;
+    uint32           unk8;
+    uint32           m_flags;
+    EventInvitesList inviteList;
+};
+
+typedef std::multimap<ObjectGuid, CalendarEventInvite> CalendarEventInviteMap;
+typedef std::map<ObjectGuid, CalendarEvent>            CalendarEventMap;
+typedef std::multimap<uint32, HolidaysEntry const*>    HolidaysList;
+
+typedef std::queue<ObjectGuid>                         EventsQueue;
+typedef std::queue<CalendarEventInvite*>               InviteQueue;
+
+typedef std::pair<HolidaysList::const_iterator,HolidaysList::const_iterator> HolidaysListBounds;
+typedef std::pair<CalendarEventInviteMap::const_iterator,CalendarEventInviteMap::const_iterator> CalendarEventInviteBounds;
+
 class Calendar
 {
+    public:
+        Calendar();
+        ~Calendar();
+        void Initialize();
+        void Update();
+
+        // searching
+        CalendarEvent*   GetEvent(ObjectGuid eventGuid);
+        EventInvitesList GetInvitesForPlayer(ObjectGuid playerGuid);
+
+        // save/load operations
+        CalendarResponseResult AddEvent(CalendarEvent* event);
+        void SaveEvent(ObjectGuid guid);
+        CalendarResponseResult AddInvite(CalendarEventInvite* invite);
+        void SaveEvents();
+        void LoadEvents();

+        // DBC operations
+        HolidaysList GetHolidaysForRegion(uint32 region);
+
+        // multithread locking
+        typedef   ACE_RW_Thread_Mutex          LockType;
+        typedef   ACE_Read_Guard<LockType>     ReadGuard;
+        typedef   ACE_Write_Guard<LockType>    WriteGuard;
+        LockType& GetLock() { return i_lock; }
+
+    private:
+        LockType                  i_lock;
+        CalendarEventMap          m_eventsMap;     // Events storage
+        CalendarEventInviteMap    m_invitesMap;    // Invites storage
+        HolidaysList              m_holidaysList;  // Holidays, sorted by region
+        EventsQueue               m_saveQueue;     // Events save queue
+        EventsQueue               m_deleteQueue;   // Events delete queue
 };
+
+#define sCalendar MaNGOS::Singleton<Calendar>::Instance()
+
 #endif