I have seen couple of different version for calculating a person's kua number. Most of them take the person's birth year. However, I have seen some formula that say if a person is born before February 4th then use the previous year of the birth year, for ex: if I was born Feb 3, 1974 then I should use year 1973 to calculate the kua number instead of 1974. So my question is which formula is more correct in this situation?