Hi JeffBett, welcome to the forum! Be sure to post up a little about yourself in the "welcome center" thread so everyone in the group can formally say hi.
Yes, Thursday the 17th would be the regularly scheduled day for this event in December. Usually people start posting about 4 or 5 days ahead of time whether they plan to make it or not. There's usually a pretty decent turnout, so I'd plan on attending if I were you.
The food trucks become more and more sparse each week during December as it gets colder and gets dark sooner, but that never stops us from having a good time.
Unfortunately, I won't be able to make it this month, as I have a work obligation that I can't get out of without ending up on bad terms with my boss.