The Robinson Services Cup semi-finals will both be played on September 5 at The Green in Comber before the final is held at the same venue on the following day.
One semi-final on the Saturday will get underway at 10:30am before the second match starts at 2:30pm.
The Sunday decider will also take place at 2:30pm.
Hosts North Down have already booked their spot in the last four alongside CIYMS while two places are still up for grabs heading into the final weekend of fixtures.
The winner of CSNI vs Waringstown will definitely qualify while Instonians will also progress if they can beat Carrickfergus at Shaws Bridge.
Weekend matches: CIYMS vs Woodvale, Instonians vs Carrickfergus, Lisburn vs North Down, Waringstown vs CSNI.