claiming my "day"

squirrly

If your friends really expect you to negotiate for wedding dates with another bride that you're not particularly close with, they're being immature.  Really.  Set your date, book your venue/vendors, send out invites, and enjoy your wedding.  Bickering over dates isn't in the planning check list.

If you REALLY want to try to head it off at the pass, just call Emily and ask her what HER date is.  If she has a different one, make a cute comment.  If she doesn't have one, say "Oh!  Well, ours is April 12th.  Only 582 days to go!"  If she has the same date as you, say, "That's an awesome date, and I'll never forget your anniversary - it'll be the same as ours." 

If she wants to change or be influenced by your date selection, that's on her.  Don't ask her to.  Don't suggest it.  Just find out if you have a conflict or not, and then let it go.