Free & Instant
Date Calculator
Add or subtract days, weeks, months, or years from any date — instantly and accurately.
Date Calculator
Choose add or subtract, pick a date, and set the duration.
Add
Subtract
Resulting Date
—About This Date Calculator
This tool adds or subtracts a chosen number of days, weeks, months, or years from any starting date — useful for planning deadlines, due dates, contract periods, or event schedules.
Common Duration Conversions
| Unit | Approx. Days |
|---|---|
| 1 Week | 7 days |
| 1 Month | Calendar month (28–31 days) |
| 1 Year | Calendar year (365 or 366 days) |
Frequently Asked Questions
Does this account for leap years?+
Yes. Since calculations use actual calendar dates, leap years (like February 29) are automatically handled correctly.
What happens when adding months to the 31st?+
If the resulting month has fewer days (e.g. adding 1 month to Jan 31), the date automatically adjusts to the last valid day of that month.