Manage Slots
Your availability for one conference: demand, unbooked students, block a range, and the slot list.
Top to bottom: the demand banner (students you need to see against usable slots), the students without a booking list, Block a stretch of time, the counts, and every slot as a row with its status and, if booked, the student and family.
See Managing your availability.
At the top, My hours lets you say the stretches you are available and blocks everything else in one go — see Set the hours you are available.