We assume the new programme was issued after the dividing date for the compensation event, as set out in the last part of clause 63.1. If that is the case, the new programme is irrelevant to the assessment of the compensation event. The assessment of the compensation event will be based upon what the accepted programme current at the dividing date showed (see first part of clause 63.5), which will be the previous accepted programme, not the new one.
With regards to the new programme, if the critical path has been reduced by 6 days, that will make the date for planned completion 6 days earlier than the previous date for planned completion. In that case this will add 6 days to the terminal float, which is the period between the completion date and planned completion as shown on this latest accepted programme. Because of the wording of clause 63.5, this is ‘owned’ by the contractor.
Of course, all of this assumes you have not rejected the new programme for a reason in clause 31.3. But, as stated above, this is only relevant for compensation events for which the dividing date falls within the period that the new programme is the accepted programme. This was a deliberate change made to ECC to ensure everybody knows what accepted programme to use.