The NBA 2020-2021 season is slated to start on December 22, 2020. The season will be split into 2 halves and will feature a play in the tournament.
Check out the NBA tentative schedule.
Dec. 11-19: Preseason games
Dec. 22-March 4: First half of regular season
March 5-10: All-Star break
March 11-May 16: Second half of regular season
May 18-21: Play-In tournament
May 22-July 22: Playoffs
source https://www.offsports.xyz/2020/11/the-nba-release-2020-21-schedule.html