My pullets lay a couple hours later each day. If one gal lays in the early AM, before I get up for a couple days, then the next day she might lay around the time I go out to check for eggs and give them water (~8 am), and the next day she won't lay until mid morning ~10 am, and then it's not until noon, and then next day around 2 pm, the next day around 4 pm -- and then she seems to hold that next days 6 pm egg until sometime early in the AM of the following day.
The cycle then repeats. Most people say that chickens lay every approx 26 hr, and I would agree with that based on my observations (egg diary) of my 4 chickens.
I know who lays which egg, based on observation of who is in the nest box. They lay radically different eggs, so I can tell them apart!