About Calendar

 In Chinese calendar, there are 12 months per year, and there are about 29 days per month. The month measured between successive new moons. There are about 354 days per year and there are about 10 days less than calendar year (solar year). So there 7 leap months every 19 years, and the lunar calendar is synchronous to solar calendar. In fact Chinese calendar is lunisolar calendar and it is depended on both moon and sun.

There is another particular solar calendar in ancient china, called the twenty-four solar terms. In fact, it really  remarks the activities in agriculture. From the names of these solar terms, farmers can immediately know what should do during this period.

Chinese calendar is not exclusive to China, but followed by many other Asian cultures as well.

The Gregorian solar calendar is an arithmetical calendar. It counts days as the basic unit of time, grouping them into years of 365 or 366 days; and repeats completely every 146,097 days, which fill 400 years, and which also happens to be 20,871 seven-day weeks. Of these 400 years, 303 common years have 365 days and 97 leap years have 366 days. This yields a calendar mean year of exactly 365+97/400 days = 365.2425 days = 365 days, 5 hours, 49 minutes and 12 seconds.