Lookup for multiple instances

I am attempting to create a timesheet to work with for a childminding business: Timesheet wb 16.07.12.xlsx

I have used VLOOKUP for each day on the Earnings worksheet to look for how long a particular child is in per day, but I have now run into problems for if a child were to come in more than once in one day (e.g. cells J8-M8 and J11-M11 in Timesheet) - only the first instance of their times is recorded (from prior example, H8 in Earnings).

I would like to have a total for how long a child is in for a given day displayed, regardless of how many times they are in during the day. I have been tinkering with the COUNTIF statement, but I can't help but wonder if there is a simpler way of doing it.



On a side note, if anyone could tell me how to clean up my (hidden) code for B20-B31, F20-F31 etc., then I would be grateful. It is comparing times to see if they overlap so the total time worked for each day is worked out in cells E20, I20 etc.