Hello,
Try the below way outs
1) If are you not having calendar week / month in the source then create a hierarchy on posting date for deriving calendar week and calendar month.
2) Now in the query Keep the hierarchy in the rows and in the column add 0DEB_CRED_LC (without any restriction) . Maintain in the calculation as *cumulative. *This will give you balances on any week or month. Draw back is that the report may be huge.
If your reporting requirement is not at Customer level then there is another way of doing it.
The AR can also be determined using GL accounts. So you can use a FIGL data source which can give you Balance based on any fiscal year period.
Let me know your comments
Regards
Gajesh