It's really common to hear "I'll be out of town from September 15 to 20 this year", though, and that's the way most (USian) people write out the date, too: Sept

It's really common to hear "I'll be out of town from September 15 to 20 this year", though, and that's the way most (USian) people write out the date, too: Sept 15, 2009.