Your price list does two jobs: it sets the price of every booking and it decides when courts can be booked. A player can book a court time only if they have a price for the whole booking. Any time without a price can't be booked.
What this means in practice
Every hour you want players to book needs a price.
Each court uses a price list, so you can open different courts, sports, days or hours just by choosing what is priced.
A player only sees a time if they have a price for every minute of it. For example, a 90-minute booking that runs 30 minutes into unpriced time isn't offered.
Prices can differ by player. Cohort prices (for example for members) can open times to some players and not to others.
Which price list is used
Nettla picks the price list from the booking's start time:
If a special period price list is active on that court on that date, Nettla uses it.
Otherwise, Nettla uses the court's standard price list.
A special period price list replaces the standard list completely while it's active. It doesn't add to it, so any hour it doesn't price can't be booked during that period.
Getting started
Create a standard price list: see "How do I set up my first price list?"
Choose that list on each court under Settings → Courts.
Add peak and off-peak prices or cohort prices if you need them.
Good to know
Until you create at least one price list, Calendar → Schedule shows "No price lists found" and "Add a price list to get started".
The Club opening hours on Settings → The Club are shown to players for information only. They don't change which times can be booked.
Changing a price list never changes the price of bookings already made.
As an admin, you can't create a court booking, match or recurring booking on unpriced time either. Use a Bespoke Booking instead.