A chronological numbering system first instituted on Earth, third planet of the Sol system. Its starting point (S.D. 1) is set at A.D. 2087, the year when Prof. Trillas Bachtein developed his warp drive system and made the idea of faster-than-light (FTL) interstellar travel a reality. The calendar was adopted on March 7, 2090, in commemoration of mankind's first FTL interstellar flight.