The idea was to align the Roman civic calendar with the solar calendar which by the time of the use of the Julian calendar were three months off. Prior to this reform the Roman civic calendar consisted of 12 months and only 355 days. After many alterations the Julian calendar was the first to bring the days of the year to what we now follow as 365. In astronomy, a Julian year (symbol: a) is a unit to measure time. It has exactly 365 1 ⁄ 4 days of 86,400 seconds each. That is the average length of the year in the Julian calendar used in Western societies in previous centuries, and for which the unit is named. New Year's Day had been celebrated on March 25 under the Julian calendar in Great Britain and its colonies, but with the introduction of the Gregorian Calendar in 1752, New Year's Day was now observed on January 1. When New Year's Day was celebrated on March 25th, March 24 of one year was followed by March 25 of the following year. Like the Easter date based on the Gregorian calendar, Orthodox Easter falls on a Sunday between March 22 and April 25 in the Julian calendar (years 1753-2400). In the Gregorian calendar, this corresponds to April 3 to May 10. In some years, Orthodox Easter falls on the same day as western Easter. The basic difference: The Julian calendar has 365 days a year, except every four years, which is a leap year, having 366 days. The Gregorian calendar adds on the rule that every year divisible by 100 is not a leap year, except those years which are divisible by 400. TL;DR: As a result of this, Julian calendar is faster than an actual solar year Icelandic calendar. A special case is the Icelandic calendar developed in the 10th century which, inspired by the Julian calendar, introduced a purely solar reckoning with a year having a fixed number of weeks (52 weeks or 364 days). This necessitated the introduction of "leap weeks" instead of Julian leap days. Tibetan calendar. 阳土猴年. (male Earth- Monkey) 1555 or 1174 or 402. — to —. 阴土鸡年. (female Earth- Rooster) 1556 or 1175 or 403. Year 1429 ( MCDXXIX) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar . Julian calendar: The Julian calendar was the 365-day calendar that Julius Caesar made official in 46 B.C. It replaced a calendar based on lunar cycles. The Julian calendar provided for a leap year with an extra day every four years. Thus, the Julian calendar included an average of 365.25 days each year. By 1582 A.D., however, the Julian In the Julian system, leap years added a 366-day leap year every four years. Gregorian calendar eliminated leap years on the century years not divisible by 400. (Example: 1700, 1800, 1900 were not 1584: July 2 Julian became July 12 Gregorian. Bishopric of Paderborn. 1585: June 17 Julian became June 27 Gregorian. Duchy of Prussia. 1612: August 23 Julian became September 2 Gregorian. Pfalz-Neuburg. 1615: February 19 Julian became March 1 Gregorian. For a list of when different countries and various regions of Germany switched to the AWUSEv.