Days Between Dates Calculator

Enter a start and end date to get the exact number of days between them, broken down into weeks, months, years, and business days.

Estimates only, not professional advice. This calculator is provided for general informational purposes and uses standard, documented formulas (shown in the sections below). It doesn't account for every factor a lender, employer, physician, or other professional would consider for your specific situation — verify important decisions with a qualified professional before relying on these numbers.

Whether you're counting down to an event, working out how long a project ran, or checking eligibility windows that depend on elapsed days, this calculator gives you the exact day count between two dates — with the breakdown into weeks, calendar months, years, and business days done for you.

How it works

  1. Enter your start and end date

    Pick both dates using the date pickers, or type them directly in the fields.

  2. Read the exact day count

    The total elapsed days appears immediately, calculated from real calendar dates rather than a fixed 30/31-day assumption.

  3. Check the other breakdowns

    See the same span expressed in weeks, full calendar months, full years, and business days (Monday-Friday only).

  4. Bookmark or share the result

    Your two dates are encoded in the page URL, so copying the address bar link preserves the exact calculation for later or for sharing.

Elapsed days versus calendar days

The most common source of confusion in a “days between dates” calculation is whether both endpoints count. This calculator reports elapsed time — the number of full days that passed between the start and end date — which matches how people usually mean “how many days until X” or “how many days since Y.” If you need an inclusive count instead (counting both the first and last day as full days), simply add 1 to the result.

Why the day count is exact, not approximate

Simpler calculators sometimes approximate using a fixed 30-day month or 365-day year, which drifts from the real answer whenever the range crosses months of different lengths or a leap year. This calculator works directly with calendar dates — comparing actual day, month, and year values — so a range from January 15 to March 15 correctly reflects that January has 31 days and February typically has 28 (or 29 in a leap year), rather than assuming every month is the same length.

Common uses for an exact day count

Eligibility windows (many visa, residency, and legal requirements specify a minimum or maximum number of days), project duration tracking, age-related calculations, subscription or trial period tracking, and simple curiosity about how long ago or how far away a date is are the most common reasons to need an exact day count rather than a rough estimate. The business-days breakdown specifically helps with anything tied to working days rather than calendar days — shipping estimates, processing windows, or billable-day counts.

Sharing a calculation

Because your two dates are encoded directly in the page’s URL as query parameters, you can copy the address bar link after entering your dates and send it to someone else, or bookmark it — reopening the link restores your exact calculation without re-entering anything.

Frequently asked questions

Does "days between dates" count both the start and end date?

This calculator shows elapsed days by default — January 1 to January 3 is 2 days, matching how "days until" and "days since" are conventionally understood. Some other calculators use an inclusive count (which would show 3 days for the same range) — if a form or requirement expects inclusive counting, add 1 to the result shown here.

Does it handle leap years correctly?

Yes — the calculation operates on actual calendar dates rather than assuming a fixed 365-day year, so a range spanning February 29 in a leap year correctly includes that extra day in the total.

What's the difference between the "days" and "business days" numbers?

The "days" figure counts every calendar day in the range. The "business days" figure counts only Monday through Friday, excluding weekends — useful for estimating delivery times, processing windows, or work-day durations, though it doesn't account for public holidays, which vary by country.

Can I calculate the difference between a past date and a future date?

Yes — enter any two dates in either order; the calculator shows the absolute difference regardless of which date comes first, and flags if the end date is earlier than the start date.

Why might this calculator disagree with a different one I tried?

The most common cause is inclusive versus exclusive counting (see above), or a calculator that uses a simplified 30-day month assumption instead of real calendar dates. This tool uses actual calendar arithmetic, so it correctly handles months of different lengths and leap years.

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