When to send out baby shower invite for Dec 27th shower?

We are traveling "home" to where both mine and my boyfriend families are for xmas. So unfortunately that's around the same time the shower is going to be. I'm not too thrilled about it being the weekend after xmas but it is what it is. The weather isn't a big worry as its in southern California but I want to send the invites out early enough for people to know/plan for it considering it's right after xmas. When is it enough time to send the invites out? No one is traveling for it except us.