Date Add / Subtract Calculator
Add or subtract years, months, weeks, days and hours from a date, with correct month-end handling.
Runs in your browserDate + duration → Date
Loading tool…
How to use the Date Add / Subtract Calculator
- Paste or type your Date + duration into the input area, or open a file from your device.
- Adjust the options above the editor if the tool offers any.
- Review the Date result, then copy it or download it as a file.
Privacy and limitations
- Your data is processed on your device and is not uploaded to any server.
Frequently asked questions
What is 31 January plus one month?
There is no 31 February, so the result is the last day of February (29 February in leap years). Years and months are applied before weeks, days and hours.
Related converters
Date Difference CalculatorCount the years, months, days, weeks, weekdays and hours between two dates.Day of the Week CalculatorFind which day of the week any date falls on, past or future, for one date or a whole list.Age CalculatorCalculate exact age in years, months and days from a date of birth, plus total days and the next birthday.Time Zone ConverterConvert a date and time between any two IANA time zones with daylight saving time handled automatically.Date to Timestamp ConverterConvert ISO 8601 and common date formats to Unix timestamps in seconds or milliseconds.ISO 8601 Date ConverterConvert dates or timestamps to ISO 8601 extended, basic, week-date and ordinal-date forms at any UTC offset.Timestamp to Date ConverterConvert Unix timestamps in seconds, milliseconds, microseconds or nanoseconds to ISO 8601, RFC or SQL dates in UTC.Unix Timestamp ConverterSee the current Unix epoch time live and convert timestamps to dates (UTC, local, relative) and dates back to timestamps.