CIYMS will begin their defence of the Lagan Valley Steels T20 Cup with a home game against Woodvale on Saturday, May 8.
The NCU confirmed the start date for the season yesterday and announced all the fixtures for the Lagan Valley Steels T20 competition, which will be completed before the Robinson Services Leagues get under way on June 12.
The T20 Cup will have all eight Premier League sides playing each other once on four successive Saturdays and three midweeks (either Thursday or Friday evenings), with the top four after the league format going through to the semi-finals on June 5. The final is on Sunday, June 6.
The winners will represent the NCU in the semi-finals of the All-Ireland T20 Cup, which will include the other three major provincial winners.
NCU general manager Angela Platt said: "We are delighted to (be the first union to) announce the first block of fixtures for the 2021 season.
"After discussions with our own clubs, and guidance from Sport Northern Ireland and the Department for Communities, we were able to develop this season's schedule and help our clubs adhere to Covid-19 regulations.
"We are pleased to have Lagan Valley Steels on board again for 2021. We would like to thank them for their continued support during these difficult times - without them we wouldn't be able to hold these competitions."
The clash at Belmont is a repeat of last year's first-round match, which CI won by 37 runs (DLS). Also on the opening day, last year's beaten semi-finalists Waringstown and Lisburn meet at The Lawn.
Running simultaneously alongside the Cup will be the LVS T20 Trophy, which will see the nine Section One clubs play each other in a knockout tournament and clubs in Section Two and Three will play for the LVS Shield and Bowl respectively in a round-robin format.
There is no confirmed date for when 50-over club cricket can start, but if it has still not been given the go-ahead for games on June 12, the initial fixtures will be played as 20-over matches.
The league fixtures are being announced today.
Meanwhile, the green light has been given for the first international action of the summer to take place on Monday, May 10, with Ireland Wolves hosting Netherlands 'A' in the first of a three-match 50-over series.
The venue will be announced on Monday, but the games will be played in the Leinster region after the green light was given by the Republic's government that elite sportspeople are exempt from mandatory quarantine.
The other games will be on May 12 and 13 and all three will be livestreamed and livescored via the Cricket Ireland match centre.
Cricket Ireland also announced yesterday that Irish insurance broker Arachas will be the title sponsor for this season's (Women's) Super Series between the Scorchers and Typhoons.
The teams will play seven Super 50 Cup games - the first this Sunday - and eight Super 20 Trophy games, with Bready hosting a T20 match on Sunday, July 25 and the NCU hosting the game on Sunday, August 1.
Lagan Valley Steels T20 Cup fixtures:
May 8: Carrickfergus v North Down, CIYMS v Woodvale, Instonians v Civil Service North, Waringstown v Lisburn.
May 13/14: Civil Service North v CIYMS, Lisburn v Carrickfergus, North Down v Woodvale, Waringstown v Instonians.
May 15: CIYMS v Instonians, Civil Service North v Lisburn, North Down v Waringstown, Woodvale v Carrickfergus.
May 20/21: Civil Service North v North Down, Instonians v Woodvale, Lisburn v CIYMS, Waringstown v Carrickfergus.
May 22: Carrickfergus v Civil Service North, CIYMS v North Down, Instonians v Lisburn, Woodvale v Waringstown.
May 27/28: CIYMS v Carrickfergus, Civil Service North v Waringstown, Lisburn v Woodvale, North Down v Instonians.
May 29: Carrickfergus v Instonians, Lisburn v North Down, Waringstown v CIYMS, Woodvale v Civil Service North.
June 5: Semi-finals. June 6: Final.