Allow dynamic booking options for Holiday Clubs

Holiday Clubs have several special requirements:

1. A lot of providers offer Early Drop Off or Late Pick Up. This feature would allow the business to set a different price for different time slots.
   

2. Booking options are typically more flexible - customers can often book any day (or half day) they choose on a holiday camp. The system should allow them to choose whichever slots they want, and then calculate the price dynamically
   

3. Discounts are often offered when a customer books a full week, multiple children or similar. The system needs to be able to factor discounts into the dynamic calculations.