As for any and every Pokemon that's evolved they cannot return back.
So if you evolved eevee into Jolteon and wanted umbreon, simply
breed Jolteon with ditto, a newborn eevee will hatch.
To make it happy, max it out on power ups,
HP UP, Protein, etc.
They can take only 10 of each, but this makes any Pokemon happy.
Chat with our AI personalities
Flareon, Vaporeon, Jolteon, Espeon, Umbreon, Glaceon, and Leafeon are the evolved forms eevee
give it a water stone
No Trainer has a Glaceon in Pokemon Platinum, You have to evolve it from your eevee given too. If it was already evolved, then you have to ask your friend if he has it to trade. If you have Eevee, then go to Snowpoint City and Go down until you see on single tree in the middle of snow then turn right, go up until you see he ice rock and lvl up eevee there and you have a glaceon
You don't get daylight. You just evolve your Pokemon (I think you mean Eevee) during the day. I evolved my Eevee into Espeon and I'm so happy!!
you must have already found this out but eevee does not evovle into anything using a moonstone. -RR14