Queens are always raised from worker eggs, i.e. eggs that would otherwise become workers. They may try to do otherwise, but it won't work. Work eggs are fertilize. To become a queen, they are fed royal jelly. The optimum timing is 4 days after an egg is layed, the day it hatches. Now, if you are talking about laying worker eggs, these are drone eggs, i.e. they hatch out to drones.