This feels like a stupid question, but I'm a bit stumped on when exactly day 21 is. This is my fifth hatch, and they all seem to be coming out on day 22 each time...or at least what I think is day 22. That might mean I need to increase the temperature in my incubator, but it also might mean I don't know how to count. So, my question is --- if you put chicks in an incubator in the morning on a Friday, is day 21 three weeks from that Thursday or three weeks from that Friday? Do you have to factor in the time it takes for the eggs to come up to the temperature inside the incubator? Does anyone know if the incubation time for chickens is really 21.5 days, or 20.5 days, or 21 days? For example, if I started those eggs in the morning, should I expect to see chicks hatching in the morning three weeks later, or in the evening? (I like watching them come out, so it would be handy to know what time of day to put them in to make that happen.) Thanks for your help!