An anniversary (from the Latin anniversarius, from the words for year and to turn, meaning (re)turning yearly; known in English since c. 1230) is a day that commemorates and/or celebrates a past event that occurred on the same day of the year as the initial event. For example, the first event is the initial occurrence or, if planned, the inaugural of the event. One year later would be the first anniversary of that event. The word was first used for Catholic feasts to commemorate saints. For mon… (More on Decennial)