Julian calendar—a calendar introduced in Rome in 46 B.C. establishing the twelve-month year:
- Down to 1582 the Julian calendar continued to be used by all Christian nations.
Julian day calendar —(Astronomy) a system of numbering days consecutively from the arbitrarily selected point of the year 4713 B.C., regardless of the various changes made in civil calendars:
- Using the astronomers’ Julian Day calendar as a common denominator … Latham has solved the conversion of virtually all (including the Chinese!) the world calendars.