How much of the scheduling interface can be customised??

I am offering academic support services. I would like to use scheduling to facilitate assignment review and feedback services. So I want students to book "services" not "appointments". And when they do this, they should be able to choose one of the 24, 48 or 72 hour booking slots on the calendar.

Can I change the language to make more sense in my context? Can I customise the scheduling process to allow one or more days for services to be performed? Any advice on this would be very much appreciated.

Squarespace Scheduling isn't a good option for this because it isn't designed for bookings than span midnight (multi-day).