The European Champions Cup semi-finals will be held on 26 September, European Professional Club Rugby announced on Wednesday.
The winners of Saracens' trip to Leinster and Clermont's quarter-final with Racing will face each other at 1200 GMT a week Saturday, with either the Irish province or one of the French clubs playing at home.
The second semi-final will have the victors of Toulouse against Ulster and Exeter Chiefs versus Northampton Saints playing later in the day at 14:30.
Record four-time champions Toulouse, the Irish side or the Chiefs will host the tie.
In the second-tier European Challenge Cup one game will be on Friday,25 September and the other a day later.
All quarter-finals for the continental competitions are being held this weekend after having been rescheduled due to the coronavirus pandemic.