No two hens are exactly alike. There are general things that normally happen but you can always find exceptions. I only have seven hens laying right now and I can find several exceptions in them.
A hen starts the egg laying process by releasing a yolk to start that incredible journey through her internal egg laying factory. Hormones trigger that release. If a hen is going to lay the next day, she normally releases that yolk about 20 minutes after she lays an egg. But there are other factors. I’m not sure what all of them are but one is tied to daylight. They are a lot less likely to release a yolk late in the day to avoid the egg needing to be laid at night.
Then not every hen lays an egg a day. Some regularly skip one or two days, while some are pretty irregular.
It takes somewhere between 23 and 30 hours for that egg to go all the way through her internal egg making factory. The average time is about 25 hours, but that can vary quite a bit. A whole lot of that time is spent in the shell gland, getting that shell laid on. A hen can speed up or delay the process if she has a reason. If she gets stressed she might lay it early, say if she is frightened. That’s one way to get a pretty light egg from a brown egg layer. The brown is the last thing to be put on the shell. Or if it is too dark or maybe another hen is hogging a certain nest, she can hold it for a while.
I had a green egg layer that would lay an egg a day for 10 to 12 straight days, skip a day, then do it again. And her egg was always in the nest by 9:00 a.m. It was easy to know which one was her egg by the color. More normal is a hen lays just a bit later every day until it gets late in the day, then she skips a day. Some are really erratic when they lay.
A couple of years back someone had a long thread on here about how the weather or events affected egg laying. Often you get a drop in egg laying the day after a stressful event, like an unusual really cold day in the winter, maybe a bad day of thunderstorms, maybe when you treat the flock for mites or lice, or after a predator scare (not necessarily a predator attack), or you shake up the pecking order by adding or taking away some chickens.
Chickkrzi I’d guess that whatever kicked off those hormones in your late layer was something late in the day, not earlier. That’s unusual but they are all unique in their own way.
Lesliejean, I don’t know how long this behavior has been going on or how long that pullet has been laying. Sometimes it takes a while for them to get their act together when they start. If it has only been a couple of times, that’s not long enough to establish a pattern. If it has been a couple of weeks or longer and she’s pretty regular about that, then that is probably her pattern.