About 24 hrs, all vents open and temp 90-95. I say 90-95 because it is better to be a little cooler than too hot.
Their egg sack, although in their belly, is absorbing and they can be without food or water the first 24.
I would give them some type of cusioning like a small wash cloth away from heat.
Remember to drain all of the water out so the babies dry.
Also, if you want to help your heart, you can run a piece of aquarium tubing through the vent hole using a pump —but if vents open, they will be fine airwise depending on how many in there. You need to tape the air movement towards heater not babies.
I don’t know how many, what type of incubator so hopefully this helps. Congrats mama! Here is to hatches on your day off!