Average till transactions with a sale per hour. Choose two periods to compare staffing demand. Green is quiet, amber steady, red busy; both grids use the same scale.
White numbers mark your busiest stretch: any hour running above three quarters of the single busiest hour on show, the slots where being one person down costs the most. A customer here = one till transaction containing a real sale (voided rings and card-machine-only receipts excluded). Each cell is an average over every trading day of that weekday in the period, so one-off spikes (match days, heatwaves) are smoothed in - the nightly forecast handles those day by day. A short period (a single week) can read noisier than a month.