Most people don't do staggered hatches unless they have a second incubator to hatch the eggs in. How many different hatch dates, how far apart are you looking at? When are the first ones due to hatch? Do you have an option to borrow or purchase a second incubator? If you could rig up a lamp in an aquarium or other closed box to maintain the right temp, you could move the eggs that are not as far along to that temporarily, but, it would be a bit of a challenge to maintain the correct temp and humidity without a thermostat. I'm not saying it can't be done, just that it will be difficult. I'd recommend that the next time, you save your eggs and set them at the same time. I wish you the best of luck.