I read about this watch during the flight from London to Dallas on Saturday and looked up the manufacturer’s web site:
ROMAIN JEROME – Day&Night

It’s a $300,000 watch that does not tell time. It is true, even a very expensive mechanical watch cannot compete for accuracy with a cheap quartz-watch. This watch takes a new approach. It is a limited-edition hand-crafted precision-engineered sculpture of kinetic art. If you want to know what TIME it is, just check your mobile…

From the web site:

With no display for the hours, minutes or seconds the Day&Night offers a new way of measuring time, splitting the universe of time into two fundamentally opposing sections: day versus night.
A new interpretation of Time based around two Tourbillons operating sequentially. The Day Tourbillon operates during the day, defining the wearer’s period of activity, and stops after twelve hours, handing over to the Night Tourbillon dedicated to man’s own private sphere.
An avant-garde approach, that is different and even disturbing.

Related link: TAG Heuer makes a mobile phone