Maintenance fees are based on calendar year, not use year. If you purchase direct, you would pay a pro-rated amount based on the number of days remaining in the calendar year between the purchase date and 12/31.
I believe you pay the prorated cost of the remaining time of the calendar year. I purchased last month, got all 2019 points, but only paid about a 3rd of the MFs.
I'd assume the same would be true even if you get 2018 buy may be mistaken.
The reason you only pay from Dec 16th is because that is when the resort opens. They can’t charge MFs until it is open. All other resorts would be pay for the remainder of 2019 from date of purchase,
And no, MFs are based on calendar year, and billed in January. The last MFs bill will be January of 2068
If a direct contract you buy today comes with 2018 points (so not Riv, Dec UY), you do not need to pay any MFs on those points. As erionm in the 2nd post stated, dues are per calendar year, not UY.
Which means that the dues for the Dec 2018 points were paid for over 20 months ago in January 2018, by whomever owned the points at that time. Could have been Disney, another owner, combination of both, etc.