Date / D-day Calculator

Calculate D-day to a target date, the difference between two dates, and add/subtract from a date โ€” all in one place. Accounts for leap years.

D-day Calculator

โ†’ โ€”

Date difference

= โ€”
Total weeksโ€”
Y/M/Dโ€”

Add / subtract

= โ€”

* All calculations are midnight-based and account for leap years and month lengths.

Frequently asked questions

Are the results accurate?

We use standard financial formulas and official rates, but results are for reference only. Confirm important decisions with a professional.

Is my input data stored?

No. All calculations run only in your browser โ€” nothing is sent to or stored on our servers.

Is it free to use?

Yes, completely free, with no sign-up or login required.