Hi,
My chick made a circular crack in the shell last night (1 day early) but hasn't made any progress in the last 9HR. I can hear it chirping, should I help it?
No, 24 hours may pass from pip to zip and be absolutely normal. I’ve personally seen 60 hours and the chick hatched fine. Also, most chicks that can’t hatch have issues and you need to be prepared to lose them (or put them down if necessary) even so. Helping too early is especially dangerous, if you start and see blood stop!
I wouldn't worry after 9 hours. As the person above said it can take 24 hours. For next time, use a pencil to mark where the air sac is so if you need to help you know where to help to avoid breaking blood vessels.
I have had success helping, but I knew the air sac was so saddled that the chick would not make it if I didn't help, so there was an even greater risk in not helping. The little chick is thriving now.