HeroTools / Productivity
Local · Private · Free

Date Calculator

Days between dates, add or subtract durations, and your exact age — calculated precisely in your browser.

Defaults to today — change it to find age on any date.

Calculated locally — nothing is sent anywhere.

Calendar math, done right

Months and years have different lengths and leap years shift February — so "3 months from now" isn't simply 90 days. This calculator uses true calendar arithmetic for adding, subtracting and measuring ages, and can count working days for project planning. It all runs in your browser: fast, private and free forever. Need help planning a project timeline? Digital Heroes can help.

About Date Calculator

Date Calculator is a free, private productivity tool that runs entirely in your web browser. Days between dates, add/subtract time, age & business-day counts. Because everything happens locally on your device, your files and data are never uploaded to a server, there is no sign-up or installation required, and it keeps working offline. It is handy for date, days between, age, duration. Like every HeroTool by Digital Heroes, Date Calculator is 100% free with no limits.

How to use Date Calculator

  1. Open Date Calculator — it runs entirely in your browser, with no signup.
  2. Fill in the fields or choose the options you want.
  3. Adjust the options to match exactly what you need.
  4. Copy or download your result — it is free, and your data stays on your device.

Frequently asked questions

Is Date Calculator free?

Yes — Date Calculator is completely free for everyone. No sign-up, no account and no usage limits.

Is it private? Are my files uploaded anywhere?

No. Date Calculator runs entirely in your browser on your own device, so your data never leaves your computer and nothing is uploaded to a server.

Does it work offline?

Yes. HeroTools is a Progressive Web App — once the page has loaded it keeps working offline, and you can install it as an app from your browser.

Do I need to install anything or create an account?

No. Just open the page and start using it. Installing it as an app is optional and only adds offline convenience.

What does Date Calculator do?

Days between dates, add/subtract time, age & business-day counts.

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