Sorry? I'm not quite sure what you mean by under 24 hours.
Eggs that have been incubated for less than 24 hours will certainly not hatch, and (fertile) eggs that have been laid less than 24 hours ago should hatch if they're put in an incubator or under a broody hen.
I think the question is whether or not eggs need to rest a day after they are laid before incubation starts. The answer is no, they do not need to rest. I regularly start incubating eggs the day they are laid and get good results.
you can hold a fertile egg in a cool place as long as it is not below 55 deg. like in a freg. then you can build up a larger number of eggs to incubate, but before you do that set them out to warm up to room temp. so you don't shock the egg. this is what I have read and working on trying it very soon