March 9-11 - Clubs may enter negotiations with certified agents of players who will be unrestricted free agents at end of league year.

March 12 - Before 4 p.m. EDT, clubs must exercise options for 2013 on all players who have option clauses in their 2012 contracts; clubs must submit qualifying offers to their restricted free agents with expiring contracts and to whom they desire to retain a right of first refusal/compensation; clubs must submit a minimum salary offer to retain exclusive negotiating rights to players with expiring 2012 contracts and who have fewer than three seasons of free agency credit; all 2012 player contracts expire. All clubs must be under the salary cap. The 2013 league year, free agency and trading period begins at 4 p.m. EDT.

March 17-20 - Annual league meeting, Phoenix

April 25-27 - NFL draft, New York

May 20-22 - NFL spring league Meeting, Boston

Sept. 5, 8-9 - 2013 NFL season begins.