Cenvat credit of march 2017 service tax bills

Dear all, This is Interesting Scenario in regards to Service Tax bills on which cenvat credit is available for the month of March 2017. As practical delay in getting bills on time, month end work we are unable to book these bills on or before 31st March. We are booking these bills now in the date 31st March. Pls note Cenvat credit of these bill can be adjusted against central excise duly payment. Now my query is If for March 2017 ER1 filing date is 10/04/2017 and Service Tax Bills are still getting booked i.e. beyond 10/04/2017. How to get credit of these bills & How to show this in Central Excise ER 1. Pls reply