Got my 2 girls on the 7th of August, 2011. Was told that they were 18 weeks old, and that they should be laying around the first of September. It is now the first of October, and still not a single egg. I'm starting to think that I got some defective hens. We'll just have to wait and see what happens.
Update: December 11, 2011...still not one single egg from these mooches! FYI, they are Rhode Island Reds. Stupid chickens.