Gina on "When to give Notice - Advice needed"

I have a quick question.
I accepted the verbal offer for a new position and I emailed and returned the offer letter Friday. I go into the office Wednesday to sign a paper copy, do the drug test, fingerprint and sign papers for the background, educational and employment check. I know that all of these will come back fine. My start date is January 7th. At this point, does it really matter when I give my 2 week notice? I can give it tomorrow (Monday) and say my last day is December 31st. This give me a week off to be with family. Or I can give it after Wednesday and have just the weekend before I start. Help please!