Well, its nothing you can change at this point. Your options are based on your ID number, not the day.
No trainer have Rotom in Pokemon Pearl, Diamond, or Platinum.
there are some trainers who have bulbasurs at the battle frontier.
The trainer Skier Lexi on Route 217 has Eevee's evolution in Pokemon Platinum. The trainers on Route 212 and 214 also have Eevee.
there are two trainers in stark mountain both of them have a gardevoir
No trainers have Manaphy. You get it by wifi event or pokemon ranger.
No trainer have Rotom in Pokemon Pearl, Diamond, or Platinum.
There are no trainers in Pokemon platinum with phione. if you want phione use action replay.
Trainers in the Snowpoint Gym or in the snowy route
there are some trainers who have bulbasurs at the battle frontier.
The trainer Skier Lexi on Route 217 has Eevee's evolution in Pokemon Platinum. The trainers on Route 212 and 214 also have Eevee.
Hmm..... I wouldn't say the Trianer House. But if you go to a Pokecenter and go to the top floor and speak to the lady in the middle, I know you can add trainers there. But not at the Trainer house, no.
there are two trainers in stark mountain both of them have a gardevoir
No trainers have Manaphy. You get it by wifi event or pokemon ranger.
No trainer that you would battle in Pokemon Platinum has a Suicune. The trainers you face in the game use Pokemon that can strictly be obtained through normal gameplay, and do not possess any legendary Pokemon.
He is on route 210 he is a ace trainer past the two ace trainers running around
On route 214, There is a trainer with a Jolteon, Flareon and a Vaporeon. The trainers name is collector Douglas
there is a trainer, a double team in fact on route 212 there are two ace trainers one of them uses a leafeon. Hope i helped