Question: how to evolve eevee to espeon in crystal?
Answer: Gold, Silver and Crystal In G/S/C, night lasts from 6 PM to 4 AM, so that's when you can get an Umbreon, whereas other times will get you an Espeon. In addition to the general methods, you can raise your Eevee's happiness by giving it a haircut with the haircut brothers in the Goldenrod Underground.