By Darren Hartwell | May 09, 2019, 2:54 PM
https://www.nbcsports.com/boston/celtics/celtics-key-offseason-dates-player-options-contract-deadlines-loom
May 14: NBA Draft Lottery (Chicago)
May 14-19: NBA Draft Combine (Chicago)
June 13: Deadline for Kyrie Irving, Aron Baynes to opt in to their 2019-20 contracts before hitting free agency. (Both players could opt out of their contracts and sign a new deal with Boston in free agency. Irving is expected to opt out of his contract regardless of where he signs to maximize his value on the open market.)
June 18: Deadline for Al Horford to opt in to his 2019-20 contract before hitting free agency.
June 20: 2019 NBA Draft
June 29: Deadline for Celtics to tender one-year qualifying offers to restricted free agents Terry Rozier, Daniel Theis, Jonathan Gibson and Brad Wanamaker.
July 1: NBA free agency begins.
July 1: Deadline to guarantee Semi Ojeyele's contract for the 2019-20 season.
July 1: The first day the Celtics can officially trade for Anthony Davis, due to the designated rookie exception rule.
July 5-15: 2019 NBA Summer League begins.
Key 2019 NBA Offseason Dates, Deadlines
By Luke Adams | April 15th 2019 at 4:02pm (CST)
https://www.hoopsrumors.com/2019/04/key-2019-nba-offseason-dates-deadlines.html
May 29
Last day for early entrants to withdraw from the NBA draft and retain their NCAA eligibility (10:59pm CT).
June 10
Deadline for all early entrants (including international players) to withdraw from the NBA draft (4:00pm CT).
June 16
Latest possible end date for the NBA Finals.
June 20
NBA draft day.
June 24
Last day for potential restricted free agents to exercise player options.
NBA awards show.
June 29
Last day for decisions on player, team and early termination options, unless individual contracts specify otherwise.
June 30
Last official day of the 2018/19 NBA league year.
Last day for teams to make qualifying offers to players eligible for restricted free agency.
Last day for players eligible for veteran extensions in 2018/19 to sign them.
July 1
Official start of the 2019/20 NBA league year.
July moratorium begins.
Free agents can begin reaching verbal agreements with teams.
Restricted free agents can sign an offer sheet.
Teams can begin signing players to rookie scale contracts, minimum salary contracts, and two-way contracts.
July 6
July moratorium ends (11:00am CT)
Teams can begin officially signing players, extending players, and completing trades.
The two-day period for matching an RFA offer sheet signed during the moratorium begins.
July 13
Last day for teams to unilaterally withdraw qualifying offers to restricted free agents.
July 15
Last day for teams to issue required tenders to unsigned first-round picks; those players become free agents on July 16 if not tendered.
August 31
Last day for teams to waive players and apply the stretch provision to their 2018/19 salaries.
August 31 – September 15
FIBA World Cup 2019 in China.
September 5
Last day for teams to issue required tenders to unsigned second-round picks; those players become free agents on September 6 if not tendered.
Late September (specific dates TBA)
Training camps open.