This project can give a (admittedly tenuous) anchor to civilization. One theory is that a complete breakdown can be addressed by some at least focusing on maintaining the clock, as a connection to a civilized past and provide a focused hope for rebuilding anew.
One day we will be visited by aliens and as they are meandering around they will come across this clock. They will look at it, turn to each other and wonder who was the a$$hat who put it there.