Add Years Calculator
Add or subtract calendar years, including leap-day dates.
Result for the values shown.
Calculations run in your browser.
What to enter
| Input | Meaning and units |
|---|---|
| Calendar date | Gregorian calendar date in YYYY-MM-DD format; years 0001 through 9999. |
| Years | integer -9998..9998 |
Understanding your result
Calendar results use the stated counting and anniversary convention. Complete months and years differ from fixed day counts.
Common mistakes
- Counting both end dates when the method excludes a boundary, or assuming all months have equal length.
Check your calculation
- Test a short known interval and a leap-day boundary; for working days, verify your holiday list.
Calculation checks, sources and review limits
What date is a given number of calendar years after or before this date?
Add or subtract calendar years, including leap-day dates.
Common uses
- Add or subtract calendar years, including leap-day dates.
How it works
Shift year by integer years; clamp Feb29 to Feb28 in nonleap year. Calendar arithmetic uses the proleptic Gregorian calendar. Explicit calendar dates are independent of local daylight-saving changes. Month/year additions clamp to the last valid day of the destination month. Timestamp arithmetic requires a stated UTC offset and excludes leap seconds.
Worked example
Enter Calendar date: 2024-02-29; Years: 1. The result is Date: 2025-02-28.
FAQ
What date is a given number of calendar years after or before this date?
Shift year by integer years; clamp Feb29 to Feb28 in nonleap year. Calendar arithmetic uses the proleptic Gregorian calendar. Explicit calendar dates are independent of local daylight-saving changes. Month/year additions clamp to the last valid day of the destination month. Timestamp arithmetic requires a stated UTC offset and excludes leap seconds.
What assumptions and limits apply?
Inputs and results must stay within the stated supported ranges.