- Count Days mode. Enter a start date and end date to count how many business days fall between them. Weekends are automatically excluded. Toggle "exclude holidays" to also skip the 11 US federal holidays. The count is inclusive of the start date but check whether your context (legal, financial, shipping) uses inclusive or exclusive counting.
- Add Days mode. Enter a start date and a number of business days to add (or a negative number to subtract). The calculator skips weekends and selected holidays to land on the correct business day. This is useful for calculating contract deadlines, invoice due dates, or shipping arrival estimates.
Example: a contract signed on Monday April 14 with a 10 business day review period ends on Friday April 25 (skipping the weekend of April 19-20). If April 21 is a holiday, the deadline moves to Monday April 28.