Calculate your exact age in years, months, days, hours, minutes, and seconds. Find days until your next birthday and your age on any future date.
Date Details
Enter your date of birth
to calculate your age
Iterate whole calendar years backwards until advancing another year overshoots reference.
Then iterate months similarly.
Remaining difference becomes days modulo month length.
(Equivalent to Gregorian calendrical subtraction libraries.)
Source reference: Gregorian adjustment rules underpinning ISO 8601 timelines used by civic registries globally.
You borrow months or days analogous to subtraction with carrying—matching how governments verify voting or drinking ages without fractional years.