Days Between Dates Calculator

It depends on context. Standard calculations count the first day but exclude the last (Monday to Tuesday = 1 day). Inclusive calculations count both days. Our calculator lets you toggle between these modes. Use inclusive mode for quarantine periods, visa durations, or event tickets. Use standard mode for hotel nights, age calculations, or chronological distance.

Convert both calendar dates into Julian Day Numbers (continuous integer counts). Then subtract the start from the end. This method automatically handles leap years and varying month lengths (28, 30, or 31 days) without manual corrections. Our calculator uses UTC-based date arithmetic to avoid daylight saving time issues.

The total inclusive span is divided by 7 to find complete weeks. Each complete week contains 2 weekend days (Saturday and Sunday). Remaining weekend days from partial weeks are then counted individually. Official holidays on weekdays are subtracted separately. In Excel, the NETWORKDAYS function handles this automatically.

Yes, but the math handles it automatically. When dates are converted to chronological numbers before subtraction, February 29 counts as a regular integer unit. You don't need to make manual corrections for date spans crossing a leap year. The calculator recognizes leap years (divisible by 4, except centuries unless divisible by 400).

A business day is any day from Monday through Friday that is not a public holiday. Saturdays and Sundays are automatically excluded. Note that this calculator excludes weekends but does not automatically detect country-specific holidays. For precise SLA or legal deadline calculations, you may need to account for local holidays manually.

Use =DAYS(end, start) for standard difference, =DATEDIF(start, end, "d") + 1 for inclusive, and =NETWORKDAYS(start, end, [holidays]) for business days. See the Excel section in the article above for detailed examples and the NETWORKDAYS.INTL variant for custom weekends.

The calculator automatically swaps the dates and shows the absolute difference. You'll always get a positive result regardless of input order. This prevents confusion and saves you from having to check which date comes first. The result represents the chronological distance between the two dates.

The calculator uses UTC-based date arithmetic, which means it treats each date as a full calendar day regardless of your local time zone. This avoids daylight saving time (DST) anomalies where a day might be 23 or 25 hours. For scenarios where the exact hour matters across time zones, use a timezone-aware tool instead.

Technically yes, but results may be inaccurate. The calculator uses the proleptic Gregorian calendar, which extends current calendar rules backward. Before October 1582, most regions used the Julian calendar, which drifted by about 10 days. For historical research involving pre-Gregorian dates, consult specialized chronological tools.

This calculator assumes a standard Monday-to-Friday work week. If your region or company uses a different schedule (e.g., Sunday-Thursday or a 4-day week), the business day count will not match your needs. In Excel, the =NETWORKDAYS.INTL function lets you define custom weekend days for these scenarios.