Cheeping inside egg

[Polk13]

How long can a chick stay in egg after it starts cheeping?

 

[justbugged]

How long since incubation started?

 

[gryeyes]

I've heard cheeping for two days, a day and a half into lock-down. But I don't know if it was ONE egg, or cheeping started in one, that egg pipped, zipped and hatched and another egg was cheeping then.

But it sure seemed like a really long time!!