I just screened in my porch using cedar wood. How long do I need to wait until I stain it? I have received some conflicting information with the time frame from 10 days to 6 months.

STAIN IT ???
Maybe you really mean put a FINISH on it???
If the wood is kiln dried, as most lumber is, then there is really no waiting period..
Cedar with just a clear finish is really beautiful... A stain will make it darker and I don't think that is what you would want...
Personally, I would use TONGUE OIL for a finish, and probably two coats... It will have a rich luster to it....Try it on a piece of wood before you do it.....

Bob Villa site

Make sure you use a penetrating stain. You can test that your cedar is ready to receive a stain by checking to see if water is absorbed into the wood. Cedar is typically ready to receive stain immediately upon installation as long as the wood is clean and dry.

Here's some more information:

"Natural -Left alone, cedar will age to a beautiful silver finish. However, if you wish to protect the wood and preserve its natural tones, look for a coating that contains ultraviolet shielding properties as well as a mildewcide. We have had exceptional results with the Sikkens Cetol system for treatment of cedar. "

"To prepare your cedar siding for stain, we recommend that you wash it first. A mill glaze remover will open up the pores on smooth faced cedar and plain old soapy water will remove the dirt from rough faced cedar preparing it for a finish."

Western Red Cedar Lumber Association I started to look around this website and it seems to have some good information for you.

Hopefully this will help.