47 years old now in 2025 - what year born?

Today, 19 December 2025 if a person is 47 years old now, what year was he born? See below:

If 47 years old, year of birth is:
1977 or 1978*

*It depends on whether he was born before or after 1 January 1978.

If now 47 years and his year of birth 1977 if he was born after 19 December 1977 until 31 december 1977 inclusively, and his year of birth is 1978 if he was born from 1 January 1978 to 19 December 1978.

Other examples:

If now 4 years, year of birth 2020 or 2021
If now 18 years, year of birth 2006 or 2007
If now 24 years, year of birth 2000 or 2001
If now 52 years, year of birth 1972 or 1973

HTML code:

BB code: