Implementation shortfall question

Is it fair to assume that there will not be a question with 2 days of realized gains/losses? If this were the case would there be 2 sets of delays costs and 2 sets of realized profits/losses?

would the delay cost for a 2 day delay just be the (3rd days opening price minus initial decision price )/initial decision price x shares bought on 3rd day/ total shares bought?

Delay cost sets = Realized sets - 1