Date Calculator
Calculate days between two dates, or add/subtract days, months, or years to a date. [NEW-2026-06-08]
Result
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Date Calculator — Free Online Tool
Calculate the number of days between two dates, or add/subtract days, months, or years to any date. The difference mode shows the result in days with approximate months and years. The add/subtract mode gives you the exact resulting date with the day of the week.
How it works
For date difference: select a start date and end date, and the tool calculates the exact number of days between them. For date arithmetic: pick a starting date, enter a number, choose days/months/years, and get the resulting date.
Use cases
Calculate how many days until a deadline or event, find your exact age in days, compute project timelines, determine invoice due dates, or figure out what date it will be 90 days from now for warranty or return period calculations.
Privacy
All calculations run locally in your browser. No data is ever sent to any server.
Related: Age Calculator, Timezone Converter, World Clock, Countdown Timer.
FAQ
Is this tool free to use?
Yes. The tool is free to use in your browser and does not require an account.
Do I need to install anything?
No. The tool runs in a normal modern browser, so you can use it on desktop or mobile without installing extra software.
Is my data uploaded to a server?
No. All processing happens locally in your browser. Your data never leaves your device.
Can I use this for production work?
Yes, but always verify the output before using it in production. Keep a copy of your original input.
What should I check before using the result?
Review the output for accuracy, formatting, encoding, and compatibility with your target system before deploying or committing.
Does this tool work offline?
Once the page is loaded, the tool runs entirely in your browser and does not need a network connection to function.