ユリウス通日
A "Julian year" should not be confused with the "Julian day", which is also used in astronomy (more properly called the "Julian day number" or "JDN"). The JDN uniquely specifies a place in time, without becoming bogged down in its date-in-month, week, month, or year in any particular calendar. Despite the similarity of names, there is almost no connection between the "Julian day numbers" and "Julian years".