How early is too early for Save the Dates?

[x_patti_x]

So I was totally planning on putting STDs in my holiday cards this year, but now I'm getting worried that ppl might think the wedding is for this year (obviously, it will say 2012.. but still). The wedding is June 2012 and about 75% of the guests will be from out of town. I wanted to give everyone a huge heads-up on the date, but now i'm thinking some ppl will think it's this year and I really don't want that.

So when did you send your STDs? and How early is too early???