Sundays and Thursday at the tranier house
Your rival challenges you at the Pokemon league Mondays and Wednesdays.
About 10 times then you can fight your rival at certain days at the Pokemon League.
No but it will be in a couple days!
You get their phone # then phone them and they will battle.
In diamond and pearl he will battle you in the fight zone on certain days of the week, in platinum, he will be found in the survival area on certain days
You can fight your rival in various places, some including:The underground in Goldenrod during the Team Rocket scareAt the Pokemon League (only on Mondays and Wednesdays)At the Dragon Den (on certain days)On your way back from Mr. Pokemon's house at the beginning of the game (right before you exit Cherrygrove City)Just before the end of Victory Road before the Pokemon League
Well, for all I know you fight your rival about 12 times and then on certain days, you get to fight him at the Pokemon League.
In Pokeathalon, you need to get 3,000 points. But it will be available in some days.
In the Safari Zone (mountain) with 18 Forest objects after 20 days.
After you do the Double Battle with your game character and your Rival against Clair and Lance in the Dragon's Den, you will then find your Rival in the Dragon's Den on Tuesdays and Thursday doing some training however he won't challenge you to a battle then. You can also find him in the Pokémon League building on Mondays and Wednesdays and he will challenge you to a battle on those days.
Pokemon league After beating him in mt moon Go up the stairs Untill your rival comes NOTE: he is only there on certain days this also works for heart gold
You can buy one with Athlete Points at the Pokeathlon Store on some days, or you can get a Waterstone from Bill's grandfather after you show him a certain Pokemon.