How bookings work — What you need before you start

One table for the bookings, with a date field that records a time of day. That is the only hard requirement. Beyond that, the more you link, the more you get back. In practice the link to the people who deliver the work is the one that pays off most: it gives you a column each on the scheduler and lets the page offer a choice of who. A link to your services gives you durations and prices. A link to your clients gives you a history you can open from any booking. A status column lets you check people in. None of it is mandatory. Leave the staff link off and the scheduler shows you a day instead of a column per person. Nothing breaks; it just does less.