Customize WebCalendar v.1.0.5

We have a regular set up of webcalendar v.1.0.5. I would like to have the time slots customized to appear as follows: 6:45 8:00 9:15 10:30 11:45 13:00 14:15 15:30 16:45 18:00 19:15 20:20 In addition, we need the functionality of the calendar to be improved. We need each day to be divided into 6 possible slots (for 6 rooms). When a new entry is to be added, a drop down box exists to pick the appropriate room. If the room is already booked for that time, it will not be able to be booked (error message appears - "this room is already booked" When a booking is done, the color shows up (existing function) on the calendar view. Each room would be color coded (your choice) so that the rooms show up on the calendar in their colors when they have been booked (color shows up). Information about the booking does not need to show up on the calendar but will show up when scrolled over - existing function.