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Add / subtract to a date

Choose a date, then add or subtract years, months, weeks and days to find the resulting date.

How Add or subtract dates works

Add or subtract from a date lets you shift any calendar date forward or backward by any combination of years, months, weeks and days, and shows the resulting date instantly. It is the everyday tool for deadline calculation, contract terms, expiry dates and scheduling ("what date is 90 days from today?").

Unlike Date difference, which measures the gap between two known dates, this tool starts from one date and applies an offset to find the other end. It follows calendar-month logic when you add months and exact day counts when you add days, so adding one month to 31 January gives 28 or 29 February rather than 2 March.

Frequently asked questions

Is the date I type sent anywhere?

No. The arithmetic runs in your browser, on your device. The date and offset you enter are never transmitted to Sunasty or any third party, and nothing is stored between visits.

Why might adding one month not give the same result as adding 30 days?

Months have different lengths. Adding one month to 31 January gives 28 or 29 February; adding 30 days gives 2 March. The tool follows calendar-month logic when you choose months, and exact day counts when you choose days, whichever matches your actual need.

How is this different from Date difference?

Date difference takes two dates and tells you the gap between them. Add or subtract from a date takes one date and an offset and finds the destination date, use this one when you know the starting point and the duration, not both endpoints.

Does it work offline?

Yes, once the page has loaded. Because the processing happens on your device, you can disconnect from the network and the tool keeps working. This is the clearest proof that your data never leaves your machine.

Is it free? Do I need an account?

It is completely free and requires no sign-up. There are no watermarks, no daily limits and no tracking cookies needed to use the tool.

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