The day after the end of the World Series marks the beginning of the 15-day period during which eligible players may elect free agency or demand a trade. Former club retains exclusive negotiating rights until 15-day filing period expires. A player who has filed for free agency may engage in general discussions with other clubs but may not discuss contract details or sign with them until the filing period ends Nov. 11. CBA, Article XX (B).
I read that as a 15 day filing period.