Mel and Oksana Split Lucia Down the Middle

12/23/2010 9:00 AM PST

Mel Gibson and Oksana Grigorieva Splitting Visitation with Lucia

'Twas the night before Christmas and all through her pad ...
Lucia was staring ... out the window for dad.

But we kid.  TMZ has learned baby Lucia will spend Xmas Eve with Oksana Grigorieva and Xmas day with Mel Gibson.

That's the plan that was hashed out, and it should go off without a glitch.  We're told the hand off is supposed to take place sometime Saturday morning. 

The baby transfer has not always gone smoothly.  Last month Mel almost called the cops on Oksana for refusing to turn Lucia over on time.

And to all a good night.