If you want the customer to be allocated a specific duration when making a booking based on the group size, you need to set this up in 'Rules dependent on number of Guests' per booking type.
To pre-set the duration for the different group sizes, go to:
Select Venue name
Select relevant booking type
Scroll down to ‘Rules Dependent on Number of Guests’ section
Enter in a rule for a certain group size by filling in ‘Guests from’ and ‘Guests to’ and then the max duration for that group size, for that booking type.
> I.e. 1 to 5 people have a max duration of 1hr30m
> 6 to 9 people have a max duration of 2hrs
> 10 to 20 people have a max duration of 3hrs
Make sure to SAVE
If you want to set up the same or similar duration on all of your Booking Types, for example, you may have the same durations for ‘Lunch’ and ‘Dinner’, you can use the 'Copy from type' button. This will copy over existing rules from a selected booking type. To do this:
> Select the 'Copy from type' button > Select the booking type you wish to copy the rules from > SAVE