Calculate # of employees each hour; sumif formulas

So the test sheet is attached below. Any advice on how to correct the function of this formula?

(IF(B77>=E7:E47,IF(C77<F7:F47,1,0),0)),(IF(B77>=O7:O47,IF(C77<P7:P47,1,0),0))

As mentioned before, everything calculates correctly except for 13:00-13:59, 14:00-14:59, and 15:00-15:59. However, if I have the employee coming in at 13:00, 14:00, or 15:00 instead of 13:30, 14:30, and 15:30 everything calculates perfect.

Thanks again.