Inclusive or exclusive changes the count by one
This is the detail behind almost every "off by a day" dispute. Exclusive counting (the default) measures the gap — the nights between the dates. Inclusive counting adds the start day too, so both ends are counted.
- Exclusive — Monday to Friday is 4 days. Use it for durations, notice periods and "days until".
- Inclusive — Monday to Friday is 5 days. Use it when both the first and last day count, like billing a hotel stay or a rental.
The other units, briefly
- Weeks — the day count divided by 7, shown as whole weeks plus leftover days.
- Months — counted by the calendar, so a whole month is honoured whatever its length; leap years are handled.
- Business days — weekdays only, which run at roughly five to every seven calendar days.
- Years — a decimal based on 365.25 days, so anniversaries and part-years read sensibly.
Common questions
How do I count the days between two dates?
Subtract the earlier date from the later one. By default the calculator counts the gap between them (exclusive), which is the number of nights, not the number of calendar days touched.
What is the difference between inclusive and exclusive counting?
Exclusive counts the days in between and adds one only at the end — Monday to Friday is 4. Inclusive counts both the start and end days — Monday to Friday is 5. Switch the toggle depending on whether both endpoints should count.
How are business days counted?
Only Monday to Friday are counted, so weekends are skipped. Public holidays are not removed unless you take them out yourself.
