Yeah, that's usually a bench warrant for failure to appear and a citation for contempt. You're prolly looking at 30 days and $500 minimum, but if the judge thinks you're a jerk...you could get 6 months and $1k.
EDIT: Advice: YOU contact the court first, apologize for your "mistake" and ask to be rescheduled. Then, if they actually buy that weak excuse and you get away with it, you really better show up on the date assigned.