Using a calendar to move events from a particiliar day to another day

I have a request to write a database which will contain a list of events for the year 2012.  Each day can only do 4 events in specific time slots. Large Calendar format.

They need a form that displays months schedule of events for the year by month/days and scolls toward the beginning of the year and toward the end so that they can view the complete year.  
1 - is there a limit for a from?
2 -any suggestions how to display a calendar with a box for each day and 3 fields with that day?
3 - I would also need to click and drag events from 1 day to another.

Thanks in advance