I have got two ex battery hens that I have retrained to perch, forage and laying in nesting boxes. That took close to two months with trial and error. Then they finally got back into lay after moulting and laid sporadically. 3 weeks ago they synchronised their laying days. Now both of them would lay from Monday to Saturday and have Sunday off three weeks in a row now. How bizzare!! Must be christian chickens...lol... Not only that their time of lay is the same each day of the week every week. 7am on monday, about 8 on Tuesday, 9am on wednesday and it goes on like that until saturday after lunch. Definitely didn't teach them to do that.