If you mean during the time in which she is trying to hatch chicks, then the maximum amount in which she can leave her eggs for a quick break is about 1-5 hours at most, depending upon the temperature and surroundings where the eggs are. The easiest way to judge is by letting your chicken have a break and continually checking the eggs she left behind for warmth. Once those eggs have lost their warmth, then the hen must come back within the next hour to warm them up again.
A broody hen will not allow the incubating eggs to cool more than a degree or two while she is off the nest. Any more than about 15 minutes and she would be in a panic to return to the nest. If she leaves the nest for any longer than that and she either has abandoned the eggs or cannot get back to the nest for some reason. Abandoned eggs can still be saved as long as you start artificial incubation within a few hours and keep the eggs under a strong light to maintain heat.
If you leave them about a week then they might sit on them.
Not even a minute!
Broody hens do and will leave the eggs for a small amount of time. They will leave to eat, drink and defecate. They will usually do this when things in the coop are calm and quiet. If a hen remains off the nest for more than an hour or so then there may be a problem. The incubating eggs cannot be allowed to cool more than a few degrees and the hen instinctively knows this. If your hen has left the nest for more than two hours you should remove the eggs and artificially incubate as soon as possible. 100.5 F with a humidity of 60% will work fine.
15 days
I have a 30 pound hen who has been laying eggs for nearly 8 years. She lays eggs that are 2 feet long and weigh 3 to 4 pounds each. The eggs are brown and white striped and smell like chocolate
no, If she did her eggs will get cold
Once a hen has been mated by the rooster her eggs will remain viable for up to 10 days or longer.
Hen sits in the hen house on eggs to keep them warm and incubate them until they hatch.
Breeding takes 30 seconds, the hen will do all this before or after mating. If you mean brooding eggs, she will leave the nest for as long as it takes to defecate, seek food and water. This usually takes less than 15 minutes and the eggs will not cool sufficiently to harm the incubation process.
More than an average human
On average, a hen lays an egg every 24-26 hours. To lay 19 dozen eggs (which is 228 eggs), it would take approximately 228 days for a hen to accomplish this feat.
Farmers used to leave one egg in the hen's nest to encourage her to have more eggs.