The second eight-hour fixture of the 2019/20 WEC at the Bahrain International Circuit, which was announced as part of a major calendar rejig in April, had been set for November 21, but has now been moved by one week to November 14.
This brings the WEC fixture clear of the two grands prix on November 29 and December 6 announced on Tuesday as part of the final, 17-race F1 schedule.
The date change means that round eight of the 2019/20 WEC season will now clash with the Sebring 12 Hours, the final event of this year's IMSA WeatherTech SportsCar Championship, as well as Super Formula's Autopolis round.
WEC boss Gerard Neveu said: "As we stated very clearly when we announced our revised calendar in April, dates were subject to further change according to the evolution of the current health crisis, or because of the calendars of other FIA world championships.
“We are very fortunate that BIC is ready and willing to be so accommodating and, indeed, welcoming to the WEC in what will be an extremely busy period for them."
Neveu stressed that a clash with Sebring was "less fortunate", adding that "the compressed racing schedules in the second half of the year have been brought about due to an unprecedented situation and we believe there will be minimal impact on both series."
The latest shift of date of the 2020 Barhain WEC fixture is the second time it has been moved, as it was originally scheduled to be round five of the 2020/21 season on December 5.
It was shifted forward and incorporated into the heavily-revised 2019/20 calendar in early April at the same time as the WEC abandoned the winter calendar format for 2021.
The 2020 Bahrain 8 Hours will start at 2:00pm and finish at 10:00pm local time.