i mean i wouldnt wait past day 25. though ive heard( dont know if its true or not just heard it) that some chickens can take 28 days? most of mine take 21 days but ive had them take 23 and one take 24. if i wake up and nothing is going on by the morning on the 25th dayu i pitch them. weve candled them and the guy who ones the incubator i put my eggs in floats them but really there isnt a need if you even wanted to wait til the night of the 25th day and nothing happens nothing will... ive never had one take past 24 days to hatch and to be honest that one didnt make it. all my healthy chicks took between 21 and 23 days to hatch. good luck.