Panthers have shelved afternoon racing due to problems preparing the East of England Showground track.
The club have staged three Sunday meetings so far this season with 1pm, 2pm and 3pm start-times.
They have all been affected by a slicker-than-desired surface which club bosses feel have hampered the home advantage of their team.
From now on Sunday meetings will begin at 5pm, starting when they entertain Rye House in the Premier League on April 26.
Promoter Ged Rathbone said: “We haven’t been able to get the amount of water required into the track.
“It means we haven’t had the home advantage we need or the exciting racing the supporters are used to.
“Pushing the start-time back gives us more time to prepare the track in the way we want it.”
That visit of Rye House will mark the end of a busy spell of racing with three meetings in four days next week.
Panthers go to Redcar for a league curtain-raiser next Thursday (April 23) before heading down to Somerset the following night for what could be a decisive final outing in the Southern Group of the Premier League Cup.
The three group winners and the best runners-up – determined by the average match points taken from completed meetings – advance to the semi-finals.
PREMIER LEAGUE CUP
P HW AW Pts
Rye House 6 3 1 13
Panthers 7 2 2 13
Somerset 6 2 1 10
Ipswich 4 2 0 7
Plymouth 5 1 0 4