How long do I wait to intervene?

[Bama chick]

The chick pipped yesterday around 4:00 pm. It is now 5 am and there has not been any progress since yesterday afternoon. She pecked a hole in the egg but that is it. I still hear peeping and see movement. I have read all the topics about if and how but have not been able to find out how long to wait before giving some assistance. What is the average length of time from pip to full hatch?
This is my only baby out of 7 eggs and I'm really worried. I've been up all night watching and listening and my heart is about to break.

 

[DAFox]

Is this chick early or early on day 21? If so, I'd wait just alittle longer. If it is day 22, I'd go ahead and help it carefully. If the membrane is stuck to it (shrink wrapped) go ahead and free it. If not, just try to zip it like a chick would.
I have watched broody Mamas help chicks out of the shell...but I also had a situation where I was incubating and had to travel to another state for a funeral. I had to "help" hatch the pipped ones and some died because it was early. My daughter who I had watching my animals was afraid of the chicks and not fond of chickens to begin with.
Good luck.
Dale-Ann

 

[Bama chick]

Today is day 22. I just wasn't sure how long it takes to actually hatch. I'll wait another hour or so.

Thank you for the reply!

 

[lockedhearts]

I had 2 pip early yesterday and did not progress at all the entire day, this morning there are 2 dry chicks under the hen. They can take 24 hours to make it out.