How do I cutoff the number of hours in advance a member can register or cancel registration from a class?

How do I cutoff the number of hours in advance a member can register or cancel registration from a class?

Tools>>System Settings>>Scheduled Appointment Settings

Member Online Registration ‑ Class cancel cut‑off (hours):

Member Online Registration ‑ Class registration cut‑off (hours):

These two options can be set to the specific number of hours that you want the cutoff to be.

Overriding Registration Cutoff Per Class