On October 4, 2011, in Cupertino, California, Apple announced the iPhone 4S. On October 7, 2011, it became available for preorder in seven initial countries (United States, Canada, Australia, United Kingdom, France, Germany and Japan) with the first delivery date set for October 14, 2011 and available on that same day for direct in-store sales in those countries.
So expect a similar time frame i would guess.