NEC ECS: What if you fail to certify Completion within one week of Completion?

NEC3 and NEC4 Contracts Time
1

What is the consequence/risk if the Contractor decides the date of Completion (for a subcontractor) but does not certify Completion within one week of this date as they are required to do under clause 30.2?

For example; If the Contractor decided that the date of Completion was 1st April for a subcontractor but failed/forgot to certify Completion within one week. He then certifies Completion on 28th April but still states that the date of Completion is 1st April?

2

It should be backdated to the date the Completion was actually achieved. The fact they did not get round to sending the piece of paper should not change liability as to when it was actually achieved.