Is it too late to retake the SAT's? When to send in the scores to UC colleges?

I’ve only taken the SAT once (in June), and my score was 1340/1600 which I’m okay with–but not perfect satisfied. But a lot of people say I should try to take it again to see if I can improve my score a bit. I missed the registration deadline for the October SAT, so now the next SAT test I can sign up for is the one in November. But I did some research online and I’ve seen some people say that you should take the SAT’s 6 weeks before the application deadline in order for the scores to be processed and submitted in time. But when I read http://admission.universityofcalifornia.edu/freshman/requirements/examination-requirement/index.html, it says I have until December 2016.

So which one is correct? Does this mean that I can send in the UC college application first and then send the SAT scores in later? Or do they expect the SAT scores to be sent simultaneously with the application? I just want to know so I can possibly retake the SATs, or just send the one score I have if it is too late already.

Yes, you can send the application first, note that you plan to take the December SAT test on the application and then send the SAT scores later.

Copied from UC Website:
Freshman applicants for fall 2017 must arrange to have official score reports sent to us by December 2016. If you plan to take an exam in December, indicate the planned test date on your admission application.