In the wild, among almost all avian species, a female builds her clutch in increments, and this can take days or even a month, and in between she lets the eggs go cold, often overnight as well. When the last egg is laid and she begins to brood, then they all begin developing at about the same rate even though some eggs are older than others. Eggs, when healthy, are much tougher and more resilient than we have been led to believe.
Chickens and guineas take around a week plus to build their clutches and the eggs are left cold in between. This is no problem for them because they are able to go into a developmentally dormant stage while in the absence of heat. Only when enough heat is applied, for long enough, do they begin to develop. Whenever that heat is removed they go into a dormant state, stasis, though if they are lacking in total health they may fail to do that, or have a limited capacity to repeatedly do that.
Healthy eggs don't begin to rot for at least a month. They are alive but dormant. Their shelf life even as infertile eggs is a good indication of how long they can last before turning. Fertile eggs last longer in my experience.
Healthy birds produce eggs which can be left to go stone cold overnight, every night, even in frosty but not freezing winters, totally miss out on incubation some days, have the incubation period drawn out over a month or more, and still survive to successful hatching. Not recommendable to allow that to happen, because it taxes the chicks in ways they should preferably not be taxed while growing, rather like a very ill human mother's impact on the child growing within her, but just providing that as an example of their ability to tolerate a non-optimal environment and still hatch. It's a bit like an inbuilt tolerance for a new mother or less instinctive hen's maternal mistakes.
There are greater chances the chicks will be a bit weaker though, and less may hatch. Most commercial strains on commercial diets do not have this vigor, and you're lucky to get a complete hatch ratio even when you give the eggs the best incubation possible (not counting using a real mother hen).
I've had eggs hatched under the circumstances I detailed there, with a terrible mother doing only part time incubation during the daytime and roosting in the main cage at night like usual, and the chicks that did hatch grew up into birds you wouldn't know had a worse start to life. They were more tired than normal when they hatched though, but soon "got up to speed".