An anniversary is the date on which an event took place or an institution was founded in a previous year, and may also refer to the commemoration or celebration of that event. For example, the first event is the initial occurrence or, if planned, the inaugural of the event. Every anniversary is a milestone, but just remember, it's less about the number and more about the quality time spent together. Celebrate those moments you've shared just the two of you, or take the time to plan an anniversary party with the friends and family who shared in your special day all those years ago.