Create master/detail entity for calendar

I have a planning application which displays the schedules in a calendar. What i would like to doe now is to create some kind of master/detail entity. In the detail the schedule for the whole month must be visible and displayed in the calendar. When i copy the master record i want to be able to change the start and end date to the next month. The new created master/detail entity will then be displayed in the next month of the calendar.

Can someone please help me or point me out in the right direction.