They can go in incubator now. They can be put in incubator 2 days after set or up to 8 days. The duck egg that was layed yesterday can be but wait a day or 2 for the newer ones. I would wait a while until you have a clutch of eggs that are needed, the eggs will be fine up to 8 days.
At last, on January 31, 1958, the United States succeeded in launching its first satellite, the Explorer. The Explorer was still slighter than Sputnik, but its launch sent it deeper into space. The Soviets responded with yet another launch, and the space race continued.
The year is 1957 and the USSR has just launched the first artificial earth satellite. In response America launches the Advanced Research Projects Agency (ARPA) within the Department of Defense (DOD) to create America's lead in science and technology. The Internet had its humble beginnings here, within ARPA's many projects.