Recurring bookings
A weekly section meeting can repeat on one or more days each week (or every few weeks), and a monthly booking can repeat either on the same date each month or on a fixed weekday — "the second Tuesday" or "the last Friday", for committee or AGM-style bookings. Need to change something without affecting the rest of the series? Edit just a single occurrence, edit that date and every date after it (a new time or keyholder starting from a certain point, say), or edit the whole series for a change that should apply from the start.