How to calculate the traditional Chinese false age. What's the matter with the false age of two years?

The traditional Chinese age is the imaginary year, the imaginary year is calculated according to the lunar calendar, the birth is 1 year, every time the Chinese New Year increased by 1 year.

The weekly age is calculated according to the Gregorian calendar, which is 0 years old at birth and increases by 1 year for every birthday.

Generally speaking, the Chinese New Year is two years older than the weekly age before the Chinese New Year's birthday, and the year after the Chinese New Year is one year older than the weekly age after the Chinese New Year's birthday.