They shouldn't lay after dark except the odd egg unless the coop is getting lots of light from somewhere. Chickens are only active while there is light and will not get off the roosts while it is dark. When they lay could be any time. Some of mine lay before I get out to open the door in the morning and some lay so late in the day I've actually locked them up and the sun is going down before their eggs appear in the nestboxes.
I am going to let my chickens free range during the day. If they lay during the day, should I put a couple of nest boxes out in the free range area? I wouldn't want to scour the land for eggs everyday if I didn't have to.
If your hens are free ranged and they want to lay in the nest boxes, (in the coop)they will. I don't think setting nest boxes 'out on the range' will do anything but teach them to start laying outside, IF they will use them.
My guess would be if they want to lay outside, they will hide the eggs so you cannot find them.