Keeping eggs

Gents, how long can you keep eggs for before giving them to foster birds? Weeks, month's? Has anyone done this and what do you have to do?

ive never done it, but I think you need to keep turning them ....maybe every day, but apart from that ive no idea, maybe some of our more experienced members can advise.

How long you can keep them i am not sure I used to keep chicken eggs for a month maybe longer but must be room temp and turned daily to keep the air pocket correct hope this helps

most pairs lay within 10 days anyway....so 10 days should be enough I am sure you can turn them for at least this period and I cant think why you would want to keep longer I know someone who did it for a full week and they hatched no bother atb

I was told keep them in the dark if doing this. In the past I kept them on shelf in wardrobe turning morning and last thing at night and from what I remember they usually hatched ok, generally kept about a week this way till something to swap with had laid.
Always done this with the canaries eggs till they had laid full clutch to stop them hatching on consecutive days and the biggest getting all the grub off parents.

Cheers gents it seems by most posts a week to ten days seems the limit for success. Many thank for the advice.