How to calculate business days
A business-day count starts with a date range, removes weekends, and then removes holidays that apply to your schedule.
Step-by-step method
- Choose the start date and end date.
- Decide whether the start and end dates should be included.
- Count Monday through Friday dates in the range.
- Remove holidays that fall on weekdays and apply to the calendar you are using.
- Document the source of the holiday list if the count is used for business planning.
BusinessDayKit uses this method in its calculator and lets you toggle listed U.S. federal holidays.
The most important choice is whether your count is inclusive or exclusive. Inclusive counts are common when you are describing a calendar period, such as the number of business days in a month. Exclusive counts are common when an event starts a clock and the next qualifying business date becomes day one.
Common choices
Inclusive counts are useful for monthly summaries. Deadline counts often exclude the start date because the first counted business day is the next qualifying date after the event starts.
Example
Suppose a range starts on Thursday, June 4, 2026 and ends on Tuesday, June 30, 2026. A weekday-only count includes 19 Monday-through-Friday dates. If U.S. federal holidays are excluded, Juneteenth on Friday, June 19 is removed, leaving 18 counted business days.
What to document
For repeatable business use, save the date range, whether endpoints were included, the holiday calendar used, and the source of the holiday list. That note makes it easier to explain why two systems may produce different answers for the same pair of dates.