NEC ECC: Under Clause 50.1 of the NEC3 ECC Contract does the assessment interval start again once the assessment required at Completion is made or is the assessment at Completion in addition to the regular assessments made at the contractual assessment interval?

Under clause 50.1 'Later assessment dates' occur at the end of each assessment interval until 4 weeks after the Defects Certificate is issued and at Completion. If Completion and the corresponding assessment occur part way through an assessment interval, am I right in assuming that the assessment interval starts again from the assessment made at Completion? E.g. if the assessment interval is 4 weeks and Completion occurs 2 weeks into the assessment interval triggering an assessment then presumably the subsequent assessment will occur after a further 4 weeks not a further 2 weeks?