Count the exact number of days, weeks, months, and years between any two dates. Includes business-day mode for project planning.
Counting days between two dates sounds simple, but the answer depends on whether you count the start and end dates inclusively, whether you want only business days, and whether the span crosses a leap year. A day counter handles all of those cases and returns totals in days, weeks, months, years, hours, minutes, and seconds. It is useful for project planning, contract terms, anniversaries, visa applications, and event countdowns.
Duration
31 days
August 21, 2026 → September 21, 2026
End date is after start date
| Unit | Value |
|---|---|
| Calendar days | 31 |
| Business days (Mon-Fri) | 22 |
| Weeks | 4.43 |
| Months (avg) | 1.02 |
| Years (avg) | 0.085 |
| Hours | 744 |
| Minutes | 44,640 |
| Seconds | 2,678,400 |
| % of a year | 8.49% |
The total-day count comes from the millisecond difference between the two midnight-aligned dates, divided by 86,400,000 (the number of milliseconds in a day). Adding one when “include end date” is checked turns an exclusive count into an inclusive count, which is what legal deadlines and hotel nights typically use.
Business days are counted by walking day-by-day from start to end and skipping Saturday (day 6) and Sunday (day 0). Public holidays are counted as regular weekdays in this version — for a holiday-aware count, layer in your local holiday calendar. Average months and years use 30.4375 and 365.25 respectively to handle the uneven month/year lengths in the Gregorian calendar.
Cross-checked against authoritative formulas (IRS, NIST, ACM) and updated for 2025/2026 tax years and rates.
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Estimates only. Calculator results are for educational and planning purposes — not professional advice. For binding decisions on taxes, investments, health, or legal matters, consult a qualified professional.
FAQ
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A day counter calculator is a free tool that counts the number of days, weeks, months, and years between two dates, with optional business-day mode that skips weekends. Our day counter calculator also returns total hours, minutes, and seconds, plus the percentage of the year completed. The day counter calculator is used for project deadlines, contract terms, anniversaries, and event countdowns.
How it works
Our day counter calculator finds the exact number of days, weeks, months, and years between two dates, with optional business-day mode that skips weekends.
Pick the first date using the start-date input. The day counter calculator uses this as day zero of the duration.
Pick the second date using the end-date input. The day counter calculator computes the gap between the two dates in days, weeks, months, years, hours, minutes, and seconds.
Toggle 'Include end date' on if your context counts both endpoints (legal terms, hotel nights). Toggle 'Business days only' to skip Saturdays and Sundays for project or HR planning.
The day counter calculator shows the total in every unit at once. The breakdown table lists calendar days, business days (if enabled), weeks, months, years, hours, minutes, and seconds. Leap years and varying month lengths are handled automatically.