my chicks are 19 weeks old now and I let them out of the coop at daylight to free range in the yard. To make sure they lay eggs in the coop best boxes instead of the nice shady hedge rows and wooded areas in the yard, could I leave them in the coop until midday? Or will they just wait to lay their eggs after I let them out after noon?
Newly laying pullets can lay any time of the day....or night.
It can take up to a month or so for things to smooth out.
Confining them to coop and run is a good idea once they start laying.
Here some tips on how to tell...
https://www.backyardchickens.com/articles/who-is-laying-and-who-is-not-butt-check.73309/
Free range birds sometimes need to be 'trained'(or re-trained) to lay in the coop nests, especially new layers. Leaving them locked in the coop for a week or so can help 'home' them to lay in the coop nests. Fake eggs/golf balls in the nests can help 'show' them were to lay. They can be confined to coop and maybe run 24/7 for a few days to a week, provided you have adequate space and ventilation, or confine them at least until mid to late afternoon. You help them create a new habit and they will usually stick with it. ..at least for a good while, then repeat as necessary.
Most of my birds
usually lay between 8am-4pm,
but hard to set your clock by a live animal.
It takes about 25 hours for an egg to form, a new ova is released shortly after an egg is laid.
A new egg could be laid approximately every 25-26 hours, so an hour or so later every day until one is laid late in the day and another ova might not be released until the following day, so a day off. BUT..very hen is different and only time will tell what a particular hen/pullets schedule might be. Not every hen/pullet lays every day..some only lay a few a week.