In the US the egg farm has 36 hours after the egg is laid to put it under refrigeration, they then have 30 days to deliver the eggs to the packer/distributor then once received the packer/distributor can put a sell by date of up to 30 more days in the future on the cartons... Meaning the eggs at the store can potentially be up to 2 months old when you purchase. The FDA recommends that you use the eggs within 3-5 weeks of the sell by date, potentially putting them at 3 months of age when used...
Room temp storage time depends highly on the actual temp and humidity where they are stored, but 2 months is not out of the question if the 'room temp' storage conditions are ideal...
