How Do You Get Glaceon On Pokemon Platinum?

Both of the previous answers are wrong. You do not need to press any button. Simply level up the evee near the icy/mossy rock, and it will evolve.

Get a evee and go to the ice covered rock in the blizzard. Go into the grass and raise the evee's level one time (you can do it with a rare candy too) then it will evolve into a Glaceon. Don't worry, it works thats how I got my Glaceon.

Hatch an evee egg or get one and simply level it up by the icy rock near snow point something ( umm... Can't remeber the name haven't played in a long time got the new pokemon soul silver) you can level it up by rare candy or give it the exp. Share and have another pokemon earn the points for it I recommend having a level one for this it levels up a lot faster with the exp.share and there you have it a glaceon and same goes with leafeon

Just level eevee up right by the icy cold rock

Go to Icy rock and level up to at least 10 and press a