Location: In a cottage waiting for my mansion over the hilltop!
Yes, it still has to do with day and night. However, you do have to trade your Eevee to Ruby/Saphire/Emerald to get it to evolve into Espeon or Umbreon.
Next time you have a question, ask it in Simple Questions. Using this thread helps us reduce spam so it helps us help you. The link to this super-thread is in my sig and in the group of stickies near the top of the FR/LG (GBA) thread listing.