Yes, that's what I though I've learned....that eggs do not start incubating UNTIL they are placed under some heat from an incubator or a hen. But eggs should not lay dormant or "resting" longer than 7-10 days without heat.All should be hatched by friday---some will be hatching late thursday. Eggs start to incubate when they are put under the broodies, or in the incubator----when they were layed has nothing to do with it---except if they got to old after they were layed before they were 'set"----Meaning I can use a egg thats layed today, one tomorrow, one the next day----1 from several more days----once I put them under the hen---they will all hatch at the same time/day if they were fertile.
Edited to add, sometimes your hatch rate can be not as good when you got 2 hens broody in one nest----sometimes it can take a little longer for some eggs to hatch, sometimes one hen ends up with all the chicks, some times not. "I" personally do not allow double setters in one nest----but those are yours----and you can if you want---LOL.
Okay, so I should start checking or listening for chicks as early as Thursday? But because there are two hens on one nest I can also expect a low hatch rate.....or a later hatch? I felt bad separating them as I only have 3 hens. The third one runs around our yard by herself a few hours each day because her girlfriends have dang gone broody!! Haha!
Thanks for you help!