Sometimes you know a person's age for a given date, and want to know what the person's age was or will be on another.
There are 2 approaches:
(1) simple
(2) accurate
Simple:
(1) If a person is X years old in a given year, then year of birth is (given year) - X.
(2) For a second date, then the age would be (second date) - (year of birth).
If the birthdate is known, then the age can be determined more accurately. In Excel this can be determined by subtracting the various dates.
