Age in Days Calculator
Calculate exact age in days, hours, minutes, and seconds — plus life milestones countdown.
Frequently Asked Questions
Is leap year handled?
Yes — the calculation uses exact millisecond differences between dates, so leap years, leap seconds, and DST transitions are all handled correctly.
How accurate is the countdown?
Accurate to the second, updating every second. Next-birthday countdown also accounts for leap days if your birthday is Feb 29.