Date Calculator
Add or subtract days, months, and years from any date. Find what date it will be after a given number of days.
Result Date
—
Year —
Month —
Day —
How to Use This Calculator
- Enter the start date (year, month, day).
- Choose Add or Subtract.
- Enter the number of days, months, and/or years to offset.
- The result date is shown in the results panel.
Formula
Result = Start Date ± (Years + Months + Days)
Years are added first, then months, then days, so month-end edge cases are handled correctly.
Example
Example: Start date Jan 31, 2024 + 1 month = Feb 29, 2024 (leap year). Add another month = Mar 29, 2024.
Frequently Asked Questions
- Enter the start date, set the operation to "Add", and enter the number of days, months, or years to add. The result date is shown instantly.
- Yes — set the Operation field to "Subtract" and the calculator will move the date backward by the amount you specify.
- Enter today as the start date and add 90 days. The result field shows the exact future date.
- Yes. JavaScript's built-in Date object handles leap years and varying month lengths automatically.
- Yes — fill in any combination. The calculator applies years first, then months, then days.