"Year anniversary" refers to the completion of one year since a specific event or occasion took place. It signifies the annual celebration or remembrance of an event that happened a year ago. Full definition
You certainly can't go wrong if you do, because this year's is the best yet, making a spectacle of the 25th year anniversary of the series. (playstationlifestyle.net)
Until then though, we want to celebrate our first year anniversary with our biggest sale yet. (gonintendo.com)
My hubby and I celebrate our 10th year anniversary in a couple of weeks, we really need to get out. (verybusymamablog.com)