Usage and Grammar

Q. I am an editor at a city magazine, and our copy department just had a spirited discussion over the phrase “last September.” The issue in which this phrase will appear hits newsstands in December 2008. Would the phrase “last September” then refer to September 2007 or September 2008? The phrases “last Tuesday,” “last week,” “last month,” and “last year” all refer to the unit of time immediately before the current one. Does “last September” merit a special consideration?

A. I don’t see why it should. But since the phrase is obviously a troublemaker, why not write “in September” or “in September 2008” instead?