280899
When there is 19 years a Chinese calender and a normal english calender should
be at the same day...my sister birthday is on 21-2-1980
in the chinese calender is 21-12...why this year
the21-2-1999 the chinese fall on 20-12?
Terence Chai, Malaysia
Actually this phenomenon is due to the extra day added to the leap year of the Geogorian Calendar we are using now. On years whose number is divisible by 4, the Geogorian Calendar will either add a day, or not, to keep it in sync with the sun, in 1000-year cycle. The Chinese Calendar, on the other hand, will add a month every 2 or 3 year, in a 19-year cycle. Thus the 2 calendars may not coincide on some of the 19th Chinese years.
Even so, they will not be more than 1 day apart, if the solar terms' 19-year cycle is not broken. In the case of Terence's sister (born 1980), 1979 has a leap month. Thus if the 18th year has a leap month, her Chinese and Gregorian birthdays on the 19th year will not be more than one day apart. 1998 has a leap month, thus her Chinese and Gregorian birthdays in 1999 are not be more than 1 day apart. It will be the same for the year 2018 if 2017 has a leap month and so on.
In fact, it is quite rare for the 19-year cycle be broken. From the period of 1905 to 2016, it has occurred only once, in the years 1984 and 1985. 1984 has a leap month, while 1985 has not, thus breaking the 1966-1985-2004 19-year cycle of leap months. That's why for people born in 1984 and 1985, it is very difficult for their Chinese and Gregorian birthdays to coincide. (At least not even until 2016)
