23 years old now in 2023 - what year born?

Today, 26 September 2023 if a person is 23 years old now, what year was he born? See below:

If 23 years old, year of birth is:
1999 or 2000*

*It depends on whether he was born before or after 1 January 2000.

If now 23 years and his year of birth 1999 if he was born after 26 September 1999 until 31 december 1999 inclusively, and his year of birth is 2000 if he was born from 1 January 2000 to 26 September 2000.

Other examples:

If now 9 years, year of birth 2013 or 2014
If now 14 years, year of birth 2008 or 2009
If now 27 years, year of birth 1995 or 1996
If now 54 years, year of birth 1968 or 1969

HTML code:

BB code: