Ulster’s crunch game with La Rochelle for control of Pool One in the European Champions Cup will be played at Kingspan Stadium on a Saturday afternoon.
The Irish Province would have been hopeful of a traditional Friday night fixture for the visit of the Top 14 side, but it will be staged on January 13 with a 1pm kick-off.
La Rochelle have led Pool One from the start of the competition, but suffered their first defeat on Sunday away to Wasps.
That left Ulster, who have won three of their four fixture to date, sitting two points behind them in second place and the winners of the Belfast game will take control of the Pool going into the final round of matches.
Ulster will go to the Ricoh Stadium to face Wasps on Sunday, January 21 with La Rochelle facing Harlequins at home both kicking off at 4:15pm (GMT).
Wasps are three points behind Ulster in the pool and who qualifies as group winner for the last eight automatcially could come down to the wire.
And that will be the case for the runners-up, although by that stage the teams vying for second place will know exactly what they have to do to go through as one of the best runners up across the five pools.
The five pool winners progress to the quarter-finals along with the three best pool runners-up.
Pool Three pacesetters Leinster host Glasgow Warriors at the RDS on January 14 before finishing away to current second-placed Montpellier six days later.
Munster top the Pool Four standings and they visit Racing 92 on January 14 before a January 21 meeting with Castres at Thomond Park.