Date Calculator
Add or subtract years, months and days from a date.
Free calculator
Age Calculator
Calculate an age in completed years, months and days between a birth date and a comparison date.
How to use this tool
Use two valid calendar dates to calculate the completed calendar duration between them.
Transparent method
Formula and method
Complete years are counted first, then complete months from the last anniversary, then remaining calendar days.
Example
From 15 January 2000 to 20 March 2026, the result is 26 years, 2 months and 5 days.
Assumptions and limits
- The birth date cannot be later than the comparison date.
- Dates are evaluated as calendar dates without time-of-day or timezone offsets.
Frequently asked questions
How are calendar dates handled?
CorelyUp uses calendar dates rather than elapsed hours, so daylight-saving time changes do not add or remove a day.
Are leap years included?
Yes. The date engine validates real calendar dates and includes leap days when they fall inside the selected range.
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Days Between Dates Calculator
Count calendar days between two dates.