I recommend to my clients that they run AP Year-end after they finish their last check run for the year. They have control over that; they don't have any control over the receipt of vendor invoices, which can drag out for weeks into the new year.
I've yet to run into a client that actually pays attention to the YTD amounts in the Statistic - YTD tab. And if they do, it would most likely be the Payments figures, not the Invoice figures.
Steve