Date Difference Calculator

Choose the start and end dates. The calculator uses calendar-day boundaries and reports the signed difference as well as the absolute number of days.

Using date-only UTC values prevents daylight-saving clock changes from turning a calendar day into a 23- or 25-hour interval.

Jack checks the interval from January 1 to January 31, 2026. The result is 30 elapsed calendar days, or 4 weeks and 2 days.

Counting both January 1 and January 31 as included dates would give 31 dates. This tool uses the elapsed difference and does not add an extra day for inclusive counting.

January 1 to January 2 is one elapsed calendar day. Two identical dates give zero. If you need to count both endpoint dates, add one to a nonnegative elapsed difference.

Weekends and holidays count. The signed difference shows whether the second date is before or after the first; the main result shows the absolute difference.

From October 1 to October 2 there is one elapsed calendar day. Counting both dates as included produces two named dates instead. Decide which convention your booking or schedule uses before reading the total.

Weekends and holidays are ordinary calendar days in this tool. A business-day calculation needs a separate holiday calendar. For hours between clock times, use the Time Duration Calculator.