Connacht and Ulster will play their postponed BKT URC fixtures against Scarlets and Edinburgh in mid-March.
The two provinces were due to face the Welsh and Scottish teams in round two at the start of October but both games were called off due to adverse weather conditions caused by Storm Amy.
Organisers have now rescheduled the matches for Friday 13 March, with both ties kicking off at 7.45pm.
Stuart Lancaster's Connacht will host Scarlets at the newly redeveloped Dexcom Stadium in Galway, while Edinburgh will welcome Ulster to Hive Stadium in the Scottish capital.
Richie Murphy's Ulster side sit fifth in the table with three wins from four, while the Westerners are in 12th with just one win to their name.
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