Sept. 1 - Active rosters expand to 40 players.
Oct. 5 - Postseason begins, wild-card playoffs.
Oct. 6 - Division series begin.
Oct. 13 - League championship series begin.
Oct. 24 - World Series begins, city of National League champion.
November TBA - Deadline for teams to make qualifying offers to their eligible former players who became free agents, fifth day after World Series.
November TBA - Deadline for free agents to accept qualifying offers, 12th day after World Series.
Nov. 7-9 - General managers meetings, Indian Wells, Calif.
Dec. 2 - Last day for teams to offer 2013 contracts to unsigned players.
Dec. 3-6 - Winter meetings, Nashville, Tenn.
Jan. 15 - Salary arbitration filing.
Jan. 18 - Salary arbitration figures exchanged.
Feb. 1-21 - Salary arbitrating hearings, Phoenix.
Feb. 14 - Voluntary reporting date for pitchers, catchers and injured players (tentative).
Feb. 19 - Voluntary reporting date for other players (tentative).
Feb. 26 - Mandatory reporting date (tentative).
March 2-11 - Teams may renew contracts of unsigned players.
March 13 - Last day to request unconditional release waivers on a player without having to pay his full 2013 salary (tentative).
March 27 - Last day to request unconditional release waivers on a player without having to pay his full 2013 salary (tentative).
March 31 - Opening day. Active rosters reduced to 25 players (tentative).
July 16 - All-Star game, Citi Field, New York.
Dec. 9-12 - Winter meetings, Lake Buena Vista, Fla.