Days Between Dates Calculator

How to Use the Days Between Dates Calculator

1. Select the beginning date in the Start Date field.
2. Select the ending date in the End Date field.
3. Choose a counting method: standard difference, include both dates, or exclude both dates.
4. Click the Count Days button.
5. Review the total counted days, complete weeks, and remaining days.
6. Use Swap Dates to exchange the selected dates.
7. Click Reset to clear the calculation and start again.

How Are the Days Between Two Dates Counted?

The Standard Difference is the elapsed calendar-day gap between two dates. For a gap of d days, Standard difference returns d, Include Both Dates returns d + 1, and Exclude Both Dates returns the greater of d – 1 or zero.

For example, the standard difference between January 1 and January 2 is one day. If both selected dates are identical, the standard difference is zero days.

Include Both Dates counts each selected date once, including both boundaries. It adds one to the standard difference, not two. January 1 to January 2 therefore gives 2 counted days.

Exclude Both Dates counts only dates strictly between the start and end dates. It subtracts one from the standard difference and never returns a value below zero. Adjacent or identical dates therefore give zero.

The tool counts calendar dates rather than elapsed clock hours. Leap years and month lengths are included; daylight-saving changes do not add or remove a calendar date.

Worked Counting Examples

June 1 to June 10, 2026 gives 9 standard days, 10 inclusive days or 8 exclusive days. With Include Both Dates selected, Complete Weeks is 1 and Remaining Days is 3, because 10 = 7 + 3.

Complete Weeks and Remaining Days use the selected counted-day total. Standard Difference and Inclusive Count always show their own totals, so the output boxes can legitimately differ.

June 1 to June 1, 2026 gives 0 standard days, 1 inclusive day and 0 exclusive days. February 28 to March 1, 2024 gives a standard difference of 2 days because February 29 lies between them.

Choosing a Method and Understanding Limits

Use Standard difference for a calendar gap, Include Both Dates for a period covering both selected dates, or Exclude Both Dates when neither boundary belongs in the count. A hotel’s nights can match a standard date gap, but this tool does not calculate accommodation charges.

Weekends and holidays are included; use Working Days to exclude them. Reverse date order produces an error. This version supports Gregorian dates in years 0100 to 9999 rather than historical local calendar systems.

To find a date a specific number of days before or after your starting date, use our Add/Subtract Date Calculator.