Date Duration Calculator
Calendar dates are compared in UTC to avoid daylight-saving changes. Inclusive mode adds one day.
Inputs and units
Enter calendar dates and choose whether the end date is counted. The difference is based on calendar dates in UTC, so daylight-saving clock changes do not alter the day count.
Calculation method
Calendar dates are compared in UTC to avoid daylight-saving changes. Inclusive mode adds one day.
Worked example
The example values are: Start date = 2026-01-01; End date = 2026-02-01; Count end date = no
- Days: 31
- Weeks and days: 4 weeks, 3 days
- Hours: 744
Assumptions and limitations
Check that the inputs and units describe your situation.
Using your result
Calculate after editing the inputs. Copy result saves the displayed values; Download result saves text, and Download CSV creates a spreadsheet-friendly report. Use Print report for a paper copy. Include inputs in copied links only when you want to share them.
Date Duration Calculator FAQs
What does count end date change?
It adds one day to the difference. The same start and end date counts as zero days normally and one day with inclusive counting.