We own 4 contracts - we bought two direct, and two resale. We chose to have a December Use Year for our first purchase, which was direct at AKV.
When we added on at BLT our guide just assumed that we wanted to keep December as our UY, and it was on our contract when we got it. We would definitely have asked for December otherwise.
Then when we went to add on at Saratoga, we waited, and waited to get a smaller (85 points) with our UY.
Finally, we bought points at HHI, and we had to hunt and search to find the right contract, with a Dec. UY -
That was especially difficult as we were looking for that contract when the new resale rule came out, so then we were under the gun to find the right contract, for the right price, with the right use year, at the right resort.
Plus we started dealing with an unscrupulous agent and had to quickly exit from that and start all over. I would imagine that poor seller from the first contract is still in possession of their contract, I would never buy it through that agent!
December seems to work really well for us, since there are no January UY's it's easier for us to think of it as a calendar year, receiving our points 'a year in advance' makes us think ahead as to how we are going to use our points!