12 years old now in 2023 - what year born?

Today, 22 March 2023 if a person is 12 years old now, what year was he born? See below:

If 12 years old, year of birth is:
2010 or 2011*

*It depends on whether he was born before or after 1 January 2011.

If now 12 years and his year of birth 2010 if he was born after 22 March 2010 until 31 december 2010 inclusively, and his year of birth is 2011 if he was born from 1 January 2011 to 22 March 2011.

Other examples:

If now 7 years, year of birth 2015 or 2016
If now 16 years, year of birth 2006 or 2007
If now 25 years, year of birth 1997 or 1998
If now 75 years, year of birth 1947 or 1948

HTML code:

BB code: