|The way you have your schedule set up might cause some problems.|
I don't know who is going to be doing the data entry, but you might want to revise your form so it makes for easy calculations.
I would suggest something like:
A B C D
1) MONDAY Week Of: 01/06/2014
2) Child's Name Time In Time Out Total Time
12) Child's Name Time In Time Out Total Time
21) Child's Name Time In Time Out Total Time
This way, you need only do a simple subtraction to get your total times: =C3-B3
Also, Each week is Dated so you know what day your using.
You can then get a weekly total using a =SUMIF()function
similar to: =SUMIF(A3:D33,"Mike",D3:D33)
Where the Range, (A3:D33) is your Week,
Your Criteria, "Mike" is the Child's Name,
and the Sum_Range, (D3:D33) is your totals column.
You can use a single tab for each month, and then do a monthly total.
Having a separate Time In and Time out, also can give you a visual cue so there should be no blank times at the end of the day. With a single Time In/Out cell you may miss a time.
There are a great number of Scheduling templates available.
Try your version of Excel.
Select File / New and you should be offered several template choices. Check'em out.
Also, MS offers a varied assortment here:
Find what suits you best and then simply modify it.