This was just posted on Twitter:
Wkdclwncar Wendell Bailey
@Rockjaw I redeemed my code on the 9th but it registers on SWTOR site as the 15th Will this change if I get in today or not?
Response:
Rockjaw Stephen Reid
@Wkdclwncar You should still get in.
1 minute ago
I'm Dec. 13 as well so this is good news for everyone in Dec.