Why do we celebrate "Easter"?

Now the post title may sound a little weird.  I'm not questioning why we celebrate Christ's rising from the grave.  If Christ didn't come back to life our faith would be nothing.  I'm questioning why we call the day Easter.

Apparently there's an ancient pagan goddess of Spring, called Eastre, had a festival in the Spring.  I checked several places about the origin of the Easter bunny and the eggs and found a few different stories.  A few websites said that rabbits and birds were symbols of fertility and that's why it was used in the pagan celebration of Spring.  On the other hand, while reading my rabbit 4-H handbook, I do a rabbit 4-H project every year, it said that the pagan goddess Eastre transformed a bird into a rabbit.  This rabbit was so thankful for the transformation that laid some colored eggs in gratitude.

So, why do Christians still call our celebration of Christ's Resurrection "Easter"?  Most of the sources I read agreed that the Christians had used the celebration of the Resurrection to replace the pagan Springtime festival--both occurred around the same time.  And because of that, we ended up with the name "Easter" and the bunny and eggs as well.

So . . . why do Christians still call it Easter?  I don't know about you, but I'm going to call this Sunday "Resurrection Day."