A LITTLE GUIDANCE
D-Day & Business Day Calculator guide
Count calendar days to an event or weekdays within a period after excluding dates you choose.
How to use
- Choose D-Day or business days and enter both dates.
- For business days, select excluded dates on the calendar or enter YYYY-MM-DD values.
- Review the date difference or the inclusive business-day count.
Worked example
- Input
- Count business days from 2026-10-05 through 2026-10-09 and exclude 2026-10-09.
- Result
- There are five weekdays minus one excluded weekday, giving four business days.
Common questions
Are the start and end dates included?
D-Day uses the difference between dates: the same date is D-Day and the next day is D−1. Business-day mode includes both endpoints.
Are public holidays excluded automatically?
No. Only Saturdays and Sundays are automatically excluded. Add public holidays or personal leave dates yourself.