Julian Calendar

Julian calendar

the calendar introduced by Julius Caesar in 46 bc, identical to the present calendar in all but two aspects: the beginning of the year was not fixed on Jan. 1 and leap years occurred every fourth year and in every centenary year

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Julian calendar [′jül·yən ′kal·ən·dər]

(astronomy)

A calendar (replaced by the Gregorian calendar) in which the year was 365.25 days, with the fraction allowing for an extra day every fourth year (leap year); there were 12 months, each 30 or 31 days except for February which had 28 days or in leap year 29.

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Julian Calendar 

(also Old Style), the calendar introduced by Julius Caesar in 46 B.C. The calendar fixed the length of the year as 365¼ days. (The actual length of the tropical year is 365 days, 5 hours, 48 min, and 46 sec.) This figure is obtained by inserting an additional day every four years—February 29 in the modern calendar. With the Julian calendar, the leap years are those that are evenly divisible by four, for example, 1900, 1904, 1972, and 1976. The difference between the New Style (Gregorian calendar) and Old Style amounted to 11 days in the 18th century and 12 days in the 19th century. In the 20th century, the difference amounts to 13 days. The shift from one style to the other has no effect on the day of the week.

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Julian Calendar 

(Old Style), a system of chronology introduced by Julius Caesar in 46 B.C. In the Julian calendar, every year that is divisible by 4, for example, 1900, 1976, and 1980, is considered a leap year; thus, the average length of a year is 365.25 days, which is 0.0078 day longer than the tropical year.

Since the error in the Julian calendar constitutes about three days every 400 years, it was replaced by the Gregorian calendar (New Style) beginning in 1582; in the USSR the Gregorian calendar was introduced February 14 (February 1 Old Style), 1918. The difference between the New and Old styles was 11 days in the 18th century and 12 days in the 19th century; in the 20th century it is 13 days. In the event of a change from one style to another, the day of the week does not change; thus, both May 1, 1979, New Style and Apr. 18, 1979, Old Style fall on Tuesday.