Count the exact number of days between two dates, or add and subtract days from any date. Free, instant, precise.
Two modes: Days Between counts the exact calendar days between two dates (including both), and Add/Subtract moves any date forward or backward by a chosen number of days.
Date arithmetic looks trivial until calendars fight back. These are the traps this calculator handles for you:
Typical uses: deadline arithmetic (“30 days from signing”), age and tenure, countdowns, subscription periods, warranty windows and historical “how long ago” questions.
Everything runs entirely in your browser. Nothing you type is ever sent to any server or stored.
Both dates are included in the count using calendar-day precision, ignoring time of day.
Yes — enter a negative number in the Add/Subtract mode, e.g. -30 for thirty days earlier.
Absolutely — count days until a contract ends, a project deadline or a visa window.
Yes, the browser's calendar logic handles months and leap years correctly.
Yes — results show the weekday of each date.
Yes, completely free with no account.