!7-20 weeks is about right. Some of the signs are, the combs and wattles getting redder, investigating the nests, and the current favorite squatting. At 17 weeks you can start checking the nest boxes. But remember they may hold off a while yet.
Its 15 to 20 weeks. The earliest I've heard for this breed is 15 weeks 4 days. This breed most of the time starts laying alittle earlier than most. I have 4 of them that are 11 weeks old. Hope this helps.
Mine are 23 weeks and still no eggs. I feed them 16% crumble mixed with 22% pellets and cracked corn twice a day. I talk to them everyday and try to bribe them with lots of clover still no eggs.
update: I finally got my first egg, 24 weeks.