Here a guide to the Eeveeloution table,
Vaporeon-evolves when you use a WaterStone on it.
Jolteon-evolves when you use a ThunderStone on it.
Flareon-evolves when you use a FireStone on it.
Espeon-Level up between 8 am and 4pm (Need to have high friendship level)
Umbreon-Level up between 8pm and 4 am(Need to have high friendship level)
Leafeon-Level up near Moss covered rock
Glaceon-Level up near Icy rock
If you are trying to get Eevee to evolve into Espeon, as long as you dont press B between 8pm and 4am, you will be good.
Hope I helped.