Tracking Hours from Employee Calendar

Hello All,

I am in the process of creating an interactive calendar for my business and want to be able to track the total number of hours an employee works in a given month. I am using drop-down menus throughout the calender to input employees.

On a separate worksheet I would like to be able to select an employee from a drop-down menu and see their entire hours for the month appear next to their name. I've seen this done on other excel workbooks but haven't been able to figure it out.

Also the hours of each shift vary each day and are being input with drop-down menus. How can I have the workbook first calculate the length of the shift, and then add all that persons shifts together to then provide the monthly total?

I'm sure I didn't describe that as clearly as I could have so I've attached the file for your reference.

Thanks in advance!