Eevee will evolve into Espeon if it has high enough friendship with you between 4 AM and 7.59 PM
Eevee will evolve into Umbreon if it has high enough friendship with you between 8 PM and 3.59 AM
Note* these times are that of which is your DS s clock
how to get higher friendship:
keep the Pokemon in your party
catch the Pokemon in a luxury ball
use stat-raising items such as calcium,protean, iron and zinc
4.have it hold a sooth bell while traveling
Level the Pokemon up
have it participate in gym battles
have it participate in Pokemon musicales
teach it a TM
9.use items like x-accuracy or x- attack on it
feed it berry's
give it sweethearts
Things that LOWER friendship:
fainting
giving it medicinal herbs such as energypowder and healpowder
Eevee's Max Hapiness like all Pokemon is 252
Its base Hapiness is 70