Choose multiple maxima from table

I am very new to VBA and not even sure where to begin for something like this.

I have a table containing sales data for three-hour periods for a restaurant. The periods shown are not disjoint, e.g., the table contains 6:00-9:00 and 6:30-9:30. I want to find those points where sales are the highest in order to schedule additional help for those "peak" periods.

I have a formula that determines how many employees can be scheduled each day, how many are used to do daily tasks (like open and close), and how many, n, are available for helping with "peak" periods.

However, if I simply choose the n highest sales values, it will undoubtedly double-(and possible triple-)cover the same period, e.g., 10:30-13:30, 11:00-14:00, and 11:30-14:30 are frequently much higher than other times, but I would only need one or possibly two additional employees to meet the additional sales.

Is there a way to choose maxima for disjoint time periods from this table?