Hens apparently have a 25 hour day, and we do find that they seem to get later and later each day, then miss a day, then start early again, so over the whole flock their laying is spread from early morning to about 3 or 4. We used to collect eggs at five, or dusk whichever comes earlier but now we have a problem with jackdaws going in the pophole and stealing the biggest eggs, so we collect every time we are passing. The hens don't like it if some are still busy but it's better than losing all our eggs.