How long will it take for muscle to build?

I noticed that my arms got a little weaker because I've been out of season for two months now and you know what they say "you don't use it, you lose it". I decided to buy a 20 pound dumbbell to do some bicep curls. I do 20 curls, followed by 15,10,5,4,3,2,1... I do this for both arms and alternate between the two. I do this everyday for the last week and a half. I noticed that my bicep is more toned but not totally built. I don't expect it to build so fast but I'm curious as to how long it should take before I start seeing results?