Exact age
Days lived
Calculate complete days, weeks, and exact age from local dates, including leap years.
Natural days · leap years included · birth date is day 0
Birth date
Enter a date, make a grid
Enter a birth date to make a shareable time map.
Enter a birth date to see the main number
No grid to draw yet.
Enter a birth date on the left (or load the sample) to see days, weeks, and a shareable link.
Methods & limits
Age is more than this year minus birth year.
Days are measured between local noons to reduce one-hour daylight-saving shifts around midnight. Exact age finds the latest birthday, advances whole months, then counts remaining days.
The birth date to itself is 0 complete days. Calling it “day 1 of life” is an ordinal convention, not a date difference.
Complete days = local noon today − local noon on birth date; the result counts completed natural-day spans.
FAQ
Days lived · FAQ
Is the birth date day 0 or day 1?
It is day 0 as a date difference and day 1 only in ordinal wording. The main result uses date difference.
Are leap years automatic?
Yes. Browser date arithmetic includes February 29 rather than treating every year as 365 days.
Why can another site differ by one day?
Common causes are counting the birth date, UTC versus local dates, and whether today has rolled over.