How long are eggs good for?

[bigspringshatchery]

After a hen lays an egg how long do I have to put in on the bator before it goes bad? I put the pointed end down and turn the eggs two the three times a day.

 

[burquechick]

I've read anywhere from 7 to 14 days. I think viability starts to drop at day 10. Temp also matters. Best temperature is around 40-70 degrees F. I just lay them on the table.