Incubation of chicken eggs take between 21-23 days to start hatching, the first crack made by the developed chick is called a pip. After the first pip it can take up to 48 hours to fully emerge from the egg. It can at times be tempting to help the new chick out of the shell but often times it best to let nature takes its course as chicks lacking to progress in hatching have beak, neck and joint malformations. A common reason to help hatch however is the last few eggs to hatch may have a dried air sack from the chicks hatches in that case I do hand hatch to help out. If you do chose to help be prepared for a NICU chick and weeks of rehabilitation.