See footnote [1]: "[1] The Long Now Foundation uses five digit dates to serve as a reminder of the time scale that we endeavor to work in. Since our flagship p

See footnote [1]: "[1] The Long Now Foundation uses five digit dates to serve as a reminder of the time scale that we endeavor to work in. Since our flagship project, the Clock of the Long Now, is meant to run well past the Gregorian year 10,000, the extra zero is to solve the deca-millennium bug which will come into effect in about 8,000 years."