“Roosevelt listened to this plea [from the head of Federated Stores to move the Turkey Day forward one week, to give merchants another week to tempt their customers], and at a Press Conference held August 14th, he said that ‘I have been hearing from a great many people for the last six years, complaints that Thanksgiving came too close to Christmas’. After Lazarus, the President had also heard from the National Retail Dry Goods Association, as well as executives of Gimbels and Lord & Taylor. Roosevelt reminded the press that Thanksgiving was still not an official holiday, and that each year the President picked the date. And, since these experts believed that adding another week to the shopping season would increase sales by 10%, Franklin announced, this year, at least, he was moving Thanksgiving to Thursday, November 23rd.
Image and excerpt from http://thepublici.blogspot.com/2010_11_14_archive.html . Learn more about the arguments for and against the date change at the link.