How long can eggs be kept in the "bull pen" before incubating?

[melentinehatric]

I kept mine on the kitchen table in a cardboard box...no special care..the sun through the window in the morning wood stove going (and its hot) ..its towards the end of winter...I gathered for 30 days...I marked with a grease pencil one X on the 2 week old to 3 week old eggs..and 2 XX on the 3-4 weeks eggs..they ALL hatched...42 or so whatever the incubator holds..its been 2 years..we had so many we havent done it again...LOL