Business Days Calculator
Count weekdays between two dates or add weekdays to a date; public holidays are not excluded.
Last updated · View algorithm, constants and default inputs (JSON)
Results
About this calculator
This calculator counts Monday through Friday and skips Saturdays and Sundays. It does not include public holidays or local working-day calendars, so check the applicable calendar before using the result for a deadline.
Worked example
calculated with the default values below
Mode Count business days between two dates · Start date 2026-10-31 · End date (for counting) 2026-12-01 · Business days to add 10 days Business days 21 days · Calendar days 31 days · Weekend days 10 days
General background references
Disclaimer
These calculators give general date results. Public holidays, working-day conventions and time-zone rules are set locally and change, so confirm against the official calendar for anything legally or contractually binding.
Implementation source
This record describes the implementation used by this page. It is not independent validation. External references, when available, support only the stated formula or definition; estimates and custom rules retain their own assumptions.
Formula and variables
N = Σ_{d ∈ [start,end), 1 ≤ weekday(d) ≤ 5} 1
- N
- Business days between dates
- start
- Start date (counted)
- end
- End date (not counted)
- weekday(d)
- 0 = Sunday … 6 = Saturday
Counts Monday through Friday and excludes weekends only. Public holidays and local working-day calendars are not included.
Frequently asked questions
Does this calculator exclude public holidays?
No. It skips Saturdays and Sundays only. It does not load public holidays or a country-specific work calendar. In between mode it counts weekdays from the earlier date up to, but not including, the later date; in add mode it advances the requested number of weekdays from the start date.