A suggestion for you. I think people are confused, because they expect an update of information. If the progress still shows 1 day left, for 9 days, then they think nothing has updated.
May you change it to this. The foreman says ok. 6 days expansion. Boss we completed four days of work. Tomorrow, Boss we complted five days of work, but now our estimate is 7 days project instead of six days.
this shows no matter how accounting records it, construction can still hide their delays in the paperwork.
Star Trek quote : When the captain asks how long it takes to complete repairs, always double your estimate. That way when he demands you finish in half the time, you have enough time to finish the repair.