The easiest way for me is to first figure out what UY my trip will happen. Then I know I can used banked points from the UY prior to the trip, points from the UY of the trip, and borrow points from the UY after the trip. So, your July 2019 trip falls in your 2019 UY. That means you can used banked 2018 points, 2019 points, and borrow 2020 points if needed!