receipt accrual for receipts whose invoiced is not received

We used receipt accrual process to generate accounting entries for receipt whose invoice is not received. There are few queries related to receipt accrual process:

1. How often we need to run receipt accrual process (Month end or daily)? If we run month end then liability will be booked at month end even we have received good at mid or start of month. Finance dept. says it would book liability at the time of receipt.

2. If we run the receipt accrual process daily and it will generate accounting entries for receipts for which invoice has not received. but if we received the invoice at the mid of month then liability will be double (Entries at the time of receipt accrual and at voucher posting). In this scenario how to do that?