A day that celebrates a past event, usually associated with marriages. On Danbooru, anniversaries are associated with how long a series has been around, with most milestones marked annually for new series, then about 5 or 10 year increments afterwards.

To celebrate the anniversary of one's birth, use the [[birthday]] tag.

h4. See also
* [[happy anniversary]]
記念日 纪念日 周年 周年庆