Being the first mechanical watch to display the hours and minutes in a digital format, the Zeitwerk manages to control the power released from the mainspring in such a way that effectively runs two escapements, the first of which runs the timekeeping in between the jumping of the minute hand. The second - in simple terms - allows a build-up of energy that can only be released every sixty seconds, when the minute needs to change. It cleverly stores enough energy every sixty minutes to move all three discs that display the time so that on the hour every hour, all three digits move at the same time.
There's even a chiming version, called the Zeitwerk Striking Time which will chime the passing quarters and the hours. The layout of the dial means that the specially designed hammers that do the striking are visible from the front of the watch, providing a visual party piece as well as an acoustic one.