H1b extension filed on friday and my visa expires on today

My extension was filed on sept 28th but m visa expires on sept 30th,2012.My question is do i need to get receipt date before sept 30th or is it ok even if i get receipt date after 30th.
I am in confusion now whether we have filed h1 on time or not.

your reciept date on the receipt notice should be on or before 30th september.