How does it work?
The whole countdown lives in the link: the title, the moment, the emoji and the colours. Nothing is saved on this site, so there is nothing to delete and no account to make. If you lose the link, make another one.
When you paste the link into a chat, the app asks this site for a preview picture. The picture is drawn at that moment with the time left on it, so it is right when it is sent. Some apps play the animated version and watch the seconds tick; others show a still.
Times are shown in whoever is looking’s own time zone. The preview picture uses UK time.