Well when you hatched the Eevee (Jolteon) did you have a Pokemon with Flame Body/Magma Armor in your team because if you have a Pokemon with Flame Body/Magma Armor the steps for hatching the egg is cut in half.
If you don't have a Pokemon with Flame Body/Magma Armor in your team with your Eevee egg it will take longer to hatch.
It takes 9,180 steps to hatch an eevee. So with Flame Body/Magma Armor you will need 4,590 steps to hatch the Eevee egg.
Hope this helps =P