If you get someone who either forgets, or loses a shift information. You can actually go into DVS and make it think the shifts were defined. If you go into Repair, open the SA file, search by text for teh employee name find teh receipt with the date and the Invoice Type of itCheck_In or itCheck_Out. I found that Client_No is actually the shift number htat was defined. If you change it to the correct shift it will see it as marked for the shift.
Another DVS-less option is to run the SALES: Cashier Performance Report. It shows TOTAL HOURS without regard to shift information.