Age

Package: DATETIME_PACKAGE. Registered by createEngine(); for a slimmer engine, register it explicitly (see choosing packages).

Age is how many whole calendar years have passed since a birth date. Solve counts them the way a person does, walking the calendar, so the answer is right across leap years, and it can give the full years, months and days instead of a single count.

Whole calendar years from a birth date, reckoned at now unless an on <date> gives another reference. in years, months and days asks for the full breakdown instead of a single count.

age of 15/06/1990 on 25/12/2030 // 40 years
age of 15/06/1990 on 26/08/2026 in years, months and days // 36 years, 2 months, 11 days

age of 15/06/1990

The count walks the calendar rather than dividing a fixed-length span, so the leap cases are right: a 29 February birth is a year older on 1 March in a non-leap year, where a 365-day division would drift. This is the calendar-aware counterpart of years between, which divides and is the right tool for a rough span.