How to make something happen when a countdown runs out

I’m trying to attach deadlines to tasks, projects, review requests, etc. Phabricator has built-in countdowns which can be attached to these objects and provide nice visuals for when things should be finished. However, nothing happens when a countdown reaches 0 (or some other threshold), the counter just silently stops.

Wondering if I can make the countdown more active, like sending an email when it has run out, or even earlier as a reminder that there is only a week, a day, etc, left before the countdown runs out.

See some discussion in https://secure.phabricator.com/T11956, but there’s currently no customer interest in this featureset so I don’t expect we’ll ship anything in this vein any time soon.