similar issue to Drupal 7 Views - Date Filter Cannot See Year
However I verified the format being used is the short date format and in the datepopup.module file, I made sure it was set to m/d/Y but I'm only seeing the month and day. Under Filter Criteria>Settings>Filter granularity = Year, it displays ok.
Currently running Views, Date, and Calendar modules in this setup. Last year someone made a patch but it no longer works
Any help is greatly appreciated!