Meaning of payments received

When we say that service tax is paid on payments received, do we mean payment based on the cheques received but in hand or the funds received in bank. What if there is a difference of 10 days between receiving and banking the cheque and the month changes in between. In which month is my laibility to pay service tax
Similarly for Cenvat Credit which is available on payment basis. Payment means issue of cheque or clearance of cheque in the bank. The party depaosited the cheques 20 days later. On which date can I avail the Cenvat credit - date of payment or date of clearance of cheque in the bank.

You can avail the the Cenvat Credit at the time of Payment but for its utilisation clearance date is considered.