Julian calendar

The Julian calendar was a reform of the Roman calendar introduced by Julius Caesar in 46 BC (708 AUC). It took effect in 45 BC (709 AUC) and was the predominant calendar in most of Europe, and in European settlements in the Americas and elsewhere, until it was superseded by the Gregorian calendar. Not to be confused with the Julian date, invented by Joseph Scaliger in 1583, a system to make it easy to compute an integer (whole number) difference between one calendar date and another calendar date.

Create Julian Calendar

public void create_julian_date_instance () {
    // Battle of Megiddo
    Chronology chrono = JulianChronology.getInstance();
    DateTime dateTime = new DateTime(1457, 5, 9, 0, 0, 0, 0, chrono);