There's a Christmas market on the 19th (and 20th) in Seegräben (Juckerfarm). I know this because I will have a stand there
It's a beautiful area and when the weather is good, the views are great. They'll have camel rides (maybe not what you're looking for!), and candle-making and there's a really nice little shop with specialty foods and a restaurant (simple, but with yummy food) as well as lots of stands.
This is the earliest market that I know about.