Correction -- the Lilian (or Lillian) epoch, depending on whether you work for or with IBM or not is not based on the Julian Epoch but rather the Gregorian epoch. However, the concept is the same. "Julianday" has its 0 defined as Noon at the prime meridian on November 24, 4714 BC. The internal datetime structure stores the datetime as the offset (in ms) from Noon on November 24, 4714 BC at "some (local) meridian" which is neither specified nor stored. The "julianday" function returns this value converted into "days" (divided by 86400000). It uses the "julianday" scale and base, but at an arbitrary and unrecorded rotational offset.