Count calendar days, whole weeks and an exact calendar interval between two dates, with optional inclusive counting.
Enter values, then calculate.
How the calculation works
Choose two Gregorian dates. Dates are converted to UTC calendar midnights so daylight-saving changes cannot add or remove a day. The day count is the absolute difference; including both dates adds one. The calendar interval uses complete months with month-end clamping and remaining days. Approximate months divide by 30.44; approximate years divide by 365.25.
Example and verification
2024-02-28 to 2024-03-01 gives 2 days, or 3 when both dates are included. 2025-01-31 to 2025-02-28 gives one calendar month under this convention. Reversing dates keeps the same absolute span.
Software checks cover the example, invalid input, zero or boundary cases, and reset in Chromium. No physical measurements or all-browser certification are claimed.
Scope and limitations
No business-day, public-holiday or working-hours calculation is included. Months and years have varying lengths; the approximate outputs are not calendar intervals. Inclusive counting affects the day/week totals, not the displayed calendar interval. Formal deadlines may use different rules.
Common questions
Does the same date equal zero or one day?
Zero elapsed days. Select the inclusive option to count that date as one day.
Technical references
Related calculators
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Maintained by GadgetsFocus. Updated 2 October 2026 with AI-assisted writing and translation review; no human native-speaker or clinical review is claimed.