What does the laying time have to do with keeping them shut in the coop?They lay all day long, they’re often not done until 4pm. Some days I go in at 4 and there are still chickens laying eggs. So keeping them in the coop would be a little hard.
The common advice to lock them in is assuming that feed and water are available in the coop, and that the coop is big enough that the chickens can stay in for several days without it being a big deal. If that is the case, just leave them shut in and see how many eggs you get.