100 years old now in 2025 - what year born?

Today, 6 November 2025 if a person is 100 years old now, what year was he born? See below:

If 100 years old, year of birth is:
1924 or 1925*

*It depends on whether he was born before or after 1 January 1925.

If now 100 years and his year of birth 1924 if he was born after 6 November 1924 until 31 december 1924 inclusively, and his year of birth is 1925 if he was born from 1 January 1925 to 6 November 1925.

Other examples:

If now 11 years, year of birth 2013 or 2014
If now 18 years, year of birth 2006 or 2007
If now 22 years, year of birth 2002 or 2003
If now 61 years, year of birth 1963 or 1964

HTML code:

BB code: