(PHP 3, PHP 4 >= 4.0.0)
FrenchToJD -- Converts a date from the French Republican Calendar to a Julian Day CountConverts a date from the French Republican Calendar to a Julian Day Count.
These routines only convert dates in years 1 through 14 (Gregorian dates 22 September 1792 through 22 September 1806). This more than covers the period when the calendar was in use.