Date of Accounting entry

Dear all,

My query is regarding date of accounting entry in case of Excise Duty liability setoff with Cenvat Receivable. Suppose my Excise Duty liability as on 30th Sept is Rs. 100. There is Rs. 50 available as Cenvat Receivable. Rest Rs. 50 will be paid through PLA. Supposing I decide to pay my liability on 5th Oct. Whether the date for passing entry for setoff off of liability with Cenvat Receivable will be 30th Sept or 5th Oct.