The guys doing this work move all over the country. So the crews come in and get the job done so they can go home for a while. In this case they have no drainage or base work to do. The only thing they have to do is remove the existing turf and cushion and replace. Removal should take about 3 days and the replacement will take about two weeks. Once the turf is down (about two days) the only thing they have to do is cut in the numbers, hash marks and logos. That is about 10 days. The only thing that will slow them up is if it rains continuously for a day or two. that is not common in August. An afternoon rain shower will only slow them up for the length of the shower. I figure 2 weeks give or take a few days. (I have been engineer for two football field installs and that was the case for both of them). It's amazing how fast this stuff goes down.