The Twitter thread (in japanese, the automated translation works quite well though) did not properly embed for me, here is a direct link to it. It has a video of the clock doing its work:

https://twitter.com/BellTreeNursing/status/69623269782428057...

On Nitter, for the un-signed-ups among us:

https://nitter.net/BellTreeNursing/status/696232697824280577

Here is a five-minute-long video about it: https://www.youtube.com/watch?v=wu2SPzv7gwY