Numbers that are counted backwards in fixed units from an arbitrary starting number to mark the time remaining before an event occurs.

On Danbooru, this usually refers to a series of images an artist or a group of artists draw with a number indicating how many days remain until a new character, event, product or series' [[release date]] or an old one's [[anniversary]] or [[birthday]]. They're usually indicated by "あとX日", meaning "X days left".

It's the opposite of [[event follow-up]], which follows the progress of an event.

Often [[second-party source|posted]] by [[official art|official]] accounts with [[guest art|commissions]] from a variety of popular artists as a way of [[promotional art|promotion]].


h4. Chronological order

* [[announcement celebration]]
* [i]countdown[/i]
* [[release celebration]]
* [[event follow-up]]
* [[ending celebration]]

h4. See also

* [[finger counting]]
カウントダウン 倒计时