How Many Days Before Need to Come Back in USA on F1

[m123]

I am on F1 visa and graduating in August 2011. My I20 is also expiring on 15, August 2011 and visa expiring in 2015. I want to go back to my home country for a month. Is there any law that i need to come back before 30 days of i20 expiration?

[Mr. Knowitall]

I believe you are looking at the recommendation that, should you wish to extend your I-20, you start that process not less than 30 days (and better, 60 or more days) before it expires.

If an F1 visa holder is traveling outside the U.S. and plans to re-enter, he should have page 3 of his I-20 signed before he travels. Each signature is valid for one calendar year.