Century leap year was introduced in 1582, but was adopted by various countries over several centuries, with the result that some countries still used the older Julian calendar while others used the Gregorian calendar. Dates prior to 1582 are generally calculated using the Julian calendar, and different countries have different conventions about dates between 1582 and their adoption of the Gregorian calendar. (See, for example, Old Style and New Style dates.) Century leap year In the Gregorian calendar, a year ending in "00" that is divisible by 400 is a century leap year, with the intercalation of February 29 yielding 366 days instead
Chinese calendar (, 29 days); stem branches for the first, eleventh, and 21st days, and the date, stem branch and time of the solar terms. The traditional Chinese calendar was developed between 771 and 476 BC, during the Spring and Autumn period of the Eastern Zhou dynasty. Before the Zhou dynasty, solar calendars were used. One version of the solar calendar is the five-elements calendar (), which derives from the Wu Xing. A 365-day year was divided into five phases of 73 days, with each phase corresponding to a Wu Xing element. A phase began with a governing-element day (), followed by