84 years old now in 2023 - what year born?

Today, 22 March 2023 if a person is 84 years old now, what year was he born? See below:

If 84 years old, year of birth is:
1938 or 1939*

*It depends on whether he was born before or after 1 January 1939.

If now 84 years and his year of birth 1938 if he was born after 22 March 1938 until 31 december 1938 inclusively, and his year of birth is 1939 if he was born from 1 January 1939 to 22 March 1939.

Other examples:

If now 10 years, year of birth 2012 or 2013
If now 15 years, year of birth 2007 or 2008
If now 21 years, year of birth 2001 or 2002
If now 37 years, year of birth 1985 or 1986

HTML code:

BB code: