That's pretty much true, tho I've had a few birds that consistently laid at about the same time of day.My experience is that it takes our birds about 26 hours between each egg, so our chickens lay about 2 hours later everyday than they did the day before. It is likely different birds laying your 6 o'clock eggs.
Just because they go into a nest, doesn't always mean they lay just then.We ordered some leg bands and put them on our Delaware chickens. They all look alike. I put a security camera in the coop (and one in the run). My wife has the camera set to alert her phone when there is activity in the coop so she can see who lays and when among other things.
Musical nests.
Yes! RoostTimeRumble!As a side note, you wouldn't believe the musical chairs that goes on up on the roost at bedtime. They usually end up in the same spots every night but my gosh all the drama!
Can be disconcerting, some keepers try to referee.