Year a leap year there are 366 days. A leap year occurs every fourth year, or leap year, during which a leap day is intercalated into the month of February. The name "Leap Day" is applied to the added day. The Revised Julian calendar, proposed in 1923 and used in some Eastern Orthodox Churches, has 218 leap years every 900 years, for the average (mean) year length of days, close to the length of the mean tropical year, days (relative error of 9·10). In the year 2800 CE, the Gregorian and Revised Julian calendars will begin to differ by one calendar
Korean New Year the winter solstice, unless there is a intercalary eleventh or twelfth month in the lead-up to the New Year. In such a case, the New Year falls on the third new moon after the solstice. Korean New Year typically falls on the same day as Chinese New Year. While Korean New Year is generally referred to as "Seollal", it has been called by many other names. They are listed in the table below. The earliest references to Korean New Year are believed to be found in the 3rd century Chinese historical work, "Records of the Three Kingdoms, Book of Wei,