When it's finished, it will play an elaborate cuckoo-like sequence for the anniversary of every year, decade, century, millennium and 10 millennia.

WSJ: What Makes Jeff Bezos Tick? A $42 Million Clock, for Starters

People who visit the clock when it is finished years from now will also be treated to a daily chime sequence that has been choreographed by musician Brian Eno, who serves on the project's board.

WSJ: What Makes Jeff Bezos Tick? A $42 Million Clock, for Starters