The traditional Chinese calendar is a lunisolar calendar: Each month starts on a new moon, and the months are numbered according to solar events, specifically, to guarantee that month 11 always contains the winter solstice. In order to accomplish this, leap months are inserted in certain years. Leap months are numbered the same as the month they follow. The decision of which month is a leap month depends on the relative movements of the sun and moon.
All astronomical computations are performed with respect to a time zone of GMT+8:00 and a longitude of 120 degrees east. Although some calendars implement a historically more accurate convention of using Beijing's local longitude (116 degrees 25 minutes east) and time zone (GMT+7:45:40) for dates before 1929, we do not implement this here.
Years are counted in two different ways in the Chinese calendar. The first method is by sequential numbering from the 61st year of the reign of Huang Di, 2637 BCE, which is designated year 1 on the Chinese calendar. The second method uses 60-year cycles from the same starting point, which is designated year 1 of cycle 1.
There is some variation in what is considered the starting point of the calendar, with some sources starting in the first year of the reign of Huang Di, rather than the 61st.
References:
Dershowitz and Reingold, Calendrical Calculations, Cambridge University Press, 1997
Helmer Aslaksen's Chinese Calendar page（http://www.math.nus.edu.sg/aslaksen/calendar/chinese.shtml）
The Calendar FAQ（http://www.tondering.dk/claus/calendar.html）
All astronomical computations are performed with respect to a time zone of GMT+8:00 and a longitude of 120 degrees east. Although some calendars implement a historically more accurate convention of using Beijing's local longitude (116 degrees 25 minutes east) and time zone (GMT+7:45:40) for dates before 1929, we do not implement this here.
Years are counted in two different ways in the Chinese calendar. The first method is by sequential numbering from the 61st year of the reign of Huang Di, 2637 BCE, which is designated year 1 on the Chinese calendar. The second method uses 60-year cycles from the same starting point, which is designated year 1 of cycle 1.
There is some variation in what is considered the starting point of the calendar, with some sources starting in the first year of the reign of Huang Di, rather than the 61st.
References:
Dershowitz and Reingold, Calendrical Calculations, Cambridge University Press, 1997
Helmer Aslaksen's Chinese Calendar page（http://www.math.nus.edu.sg/aslaksen/calendar/chinese.shtml）
The Calendar FAQ（http://www.tondering.dk/claus/calendar.html）
