One night I was playing my Soul Silver and my Eevee started to evolve. I wanted her to be an Umbreon. And it was night in the game. So, I'm wondering why my Eevee evolved at night and still became an Espeon.
Maybe it happened because Night in the Pokemon game is from 8:00 PM to 3:59 AM, and daytime is from 4:00 AM to 7:59 PM
Your internal clock may be messed up and not aligned with your game. Did you change the time after you started the game?