This is very helpful. Thank you! Yes, I would have thought you would have to wait until April. I suppose though, at that point, you would only have 2018 & 2019 points available for that trip, right? Just want to make sure I am finally getting this.
That is correct, UNLESS you "bank" your 2017 points into 2018. You can have up to 3 years worth of points to use at any given time should you plan it that way.
Expanding on my previous example, "I am not going in my 2017 UY". As my example was phrased, with an April UY, that means you have 8 months (until November 30th, 2017) to bank your points. Mind you that banking CANNOT be undone (Nor can borrowing).
So, come end of November 2017, you call or go on line, and bank your points. Assuming a 100 point contract, you will now have 200 points in your 2018 UY. The 100 points that you banked, will be the first used for any reservation in that 2018 UY. They will also EXPIRE at the end of the 2018 UY, so on March 31st, 2019, the last day of your 2018 Year, any unused points banked into 2018 from 2017 expire. (This is called breakage)
But, moving forward, your October 1st, 2018 reservation (100 point contract). You could call at the end of October, 2017, and bank your 2017 points...so you now have 200 in 2018. November 1st 2017 is the first day you can make your reservation for October 1st, 2018. On that day, you can also borrow your 2019 points (no waiting until April), so, you could make a reservation that uses up to 300 points, as your reservation is in 2018 UY, and you have 100 banked points, 100 current points, and 100 future points you could use.
The caveat here is that 200 of those points are from a different UY. Since banking and borrowing CANNOT be undone, should you cancel this trip, you have 200 points that expire March 31st, 2019. (The 100 current points can still be banked). So, using 3 years worth of points in 1 year could increase your change of losing points due to breakage (points expiring before they are used). It is not a death sentence, but it is lost money.