Having some experience of working with supermarkets, they will ask the contractor to pre-agree a completion date and there will be heavy cost penalties if they miss that date. Therefore, the site manager will be under huge pressure to get everything completed in time, plus i would also hazard a guess the heavy equipment such as fridges and ovens will be going in towards the end of this week / weekend. If the store opens on the 18th, final fit, stocking etc will take place on the 17th, so expect lots of workers, staff, vans, lorries and general bustle in the preceding 24hrs.