10 years old now in 2023 - what year born?

Today, 22 March 2023 if a person is 10 years old now, what year was he born? See below:

If 10 years old, year of birth is:
2012 or 2013*

*It depends on whether he was born before or after 1 January 2013.

If now 10 years and his year of birth 2012 if he was born after 22 March 2012 until 31 december 2012 inclusively, and his year of birth is 2013 if he was born from 1 January 2013 to 22 March 2013.

Other examples:

If now 11 years, year of birth 2011 or 2012
If now 15 years, year of birth 2007 or 2008
If now 20 years, year of birth 2002 or 2003
If now 42 years, year of birth 1980 or 1981

HTML code:

BB code: