Peak hours are the parts of the week that everyone wants: Saturday morning, late-night Thursday, the hour after school pick-up, lunchtime in a city salon, the fortnight before Christmas. Demand for those hours is higher than the chairs available, and the phone is busiest at exactly the moment everyone is with a client. The quiet hours, often early in the week, have the opposite problem.
Knowing your peaks lets you staff them, price them and protect them. A peak slot given to a client who would happily come on a Tuesday is a peak slot that a Saturday-only client cannot have.
In practice
A barbershop is open 51 hours a week, 9 to 6 on weekdays and 9 to 3 on Saturday. It logs every call for two weeks. Of 180 calls, 74 come between 3 pm and 6 pm on weekdays and 41 on Saturday before noon. Those windows hold 115 of the 180 calls, about 64%, in just 18 of the 51 opening hours, and they are when both barbers are busiest.
The shop makes three changes. Saturday mornings go to booked clients only, with walk-ins after noon. Regulars who are flexible are offered a standing weekday time. And during the 3 to 6 pm window, unanswered calls divert so that callers are not lost while both chairs are full. Track chair utilisation by day alongside this, so you can see whether the quiet hours fill as the peaks are protected.