VBA Code To Break Down Scheduled Shifts By Hour With Rates

My vision is to have a "graph" (doesn't have to be a graph, it can be a row of cells) at the bottom of my worksheet that represents how many hours I am spending per hour, and the amount of money I am spending in each hour.

If column A represents the shifts (ie: 12:00pm to 4:00pm), and column B represents the hourly rate, is it possible to use code to look down the columns and break it down so that I can see that between 12:01 and 1:00, I am spending this many hours @ this much money, and between 1:01 and 2:00, I am using this many hours @ this much money, etc, etc.....Not all of the shifts would be this clean. Shifts can begin or end on the quarter and half hours.....Many shift will begin before noon, and some shifts on the weekend will end after midnight...if that matters.

Thanks in advance.