Your Age
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Total Days
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Next Birthday In
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Difference
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Total Days
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Total Weeks
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Resulting Date
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Frequently Asked Questions
Your birth date is compared with today's date using calendar rules: first the year difference, then the month difference, then the day difference is taken; if the day or month comes out negative, a borrow is made from the previous month/year. This is the standard calendar method used by most age calculators.
All total-day and date add/subtract operations use the calendar's real month lengths (including that February has 29 days in a leap year and 28 otherwise) — so people born on February 29 and date ranges spanning leap years are calculated correctly.
No. The dates you enter are processed without a time component (only year/month/day) and comparisons are made against a fixed reference (UTC); this way your browser's time zone never shifts the calculated day count by a day.
Your birth month and day are placed in this year's (or next year's, if it has already passed) occurrence; if it's a leap-year-specific date like February 29, it's rounded down to the last day of that month (February 28) in non-leap years. The number of days between today and that date is shown; if it's exactly today, a "Today is your birthday!" message appears.
No. All calculations in this tool are done entirely in your browser with JavaScript — no date or result is ever sent to OpenMoon's servers or anywhere else.
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