I believe Google’s data would reflect number of people hanging out inside more than number of customers passing through, since a customer that stays 10x as long has 10x the impact on average number of people inside the building. 11-6 sounds right for times the seating area is most full, but I’d imagine the biggest rush of in-and-out customers is just before work hours. Fortunately, there’s a Starbucks near me that I happen to know has had its lobby closed for a year or two due to a high crime rate, and Google’s data for it does indeed show a strong peak from 7 to 10.