I used to raise chickens. In fact until about 3 months ago I had nearly 200 chickens. I raised them for farm fresh eggs and also because I like to know that my table is set with the most healthy possible chicken I can get.
To answer your question it is supposed to take a chicken 36 hours to lay an egg. Though I have had some that lay an egg every 24 hours.
For every day and a half you get one egg per chicken. When you get a chicken that gets broody, (wants to set) she will lay anywhere from 6 to as many as 18 eggs before setting.
18 eggs at a day and a half each comes to 27 days, that is 4 weeks. I have had eggs inside for that long before starting my incubators up and had nearly a 95% hatch.
You should be able to keep eggs unrefrigerated for 6 weeks without them spoiling but that is pushing a bit. If you do that be sure to check them by placing them is a glass of water to see if they float or not.
Hope that helps.