Production Weekly has revealed that the production behind 'Breaking Dawn' "has opened up new production offices in Baton Rouge and that filming is scheduled from November 1 - March 15.
This ties in with an earlier Gossip Cop article that "The actors arrive on set in October for rehearsal, hair and make-up tests, etc.” Shooting begins in November, and “this has always been the plan.”
“There may be some confusion because actors have said in interviews that they start in October,” explains our insider. “Prep for the actors starts in October, [but] production has always been scheduled for November.”
Source and Source via Breaking Dawn Movie