Business days calculator
Count business days forward or backward from any date, in your local timezone, with a selectable working week and an optional public-holiday adjustment drawn from official calendars (United States, United Kingdom (England & Wales), United Kingdom (Scotland), United Kingdom (Northern Ireland), Ireland, France, Canada, Australia, and Uganda) or your own custom holiday list.
Working days
Working days only. The start date is day 0 and is not counted.
Type a date or pick one
Counted in UTCstart date not countedMonday to Fridayno holiday calendar
Assumptions and sources
- Timezone
- UTC (UTC)
- Counting
- Start date not counted
- Valid for
- 2026-09-04
- Working week
- Monday to Friday
- Holiday calendar
- None chosen
- Holidays excluded
- None in this span
- Result ID
- tw1-d49c3d2367eaee14
14 calendar days, counting weekends Holiday calendar: None
10 business days after September 4, 2026 is Friday, September 18, 2026.
Calculation receipt
- Answer
- Friday, September 18, 2026
- Operation
add_business_days- Inputs
- date: 2026-09-04
- Timezone
- UTC
- Convention
- Whole calendar days, midnight to midnight; today = day 0 (not counted)
- Workweek
- mon-fri
- Holiday calendar
- None
- Valid for
- 2026-09-04 in UTC
- Computed at
- 2026-09-04T04:41:47.307Z
- Versions
- engine 1.0.0 · holiday dataset 2026.07.2
- Result ID
Same inputs, engine, and dataset always reproduce this ID; anyone can verify the answer from the fields above.
How business days are counted
The calculator uses the everyday convention: the start date is day 0 and is not counted, and each following Monday-to-Friday weekday counts as one business day. So 10 business days after a Monday is the Monday two weeks later, and 1 business day after a Friday is the next Monday. Counting backward works the same way in reverse. This exclusive convention matches how most offices read "within N business days", but contracts sometimes spell out something different, see inclusive vs exclusive day counting and how to count business days correctly for the details.
Edge cases that move the date
- Starting on a weekend. The count simply continues from the next weekday: 1 business day after a Saturday is Monday, the Saturday and Sunday are never counted.
- Holiday observance. When a public holiday lands on a weekend, the day off usually moves. In 2026, July 4 falls on a Saturday and US federal offices observe it on Friday, July 3, so the holiday-aware count skips that Friday, not the printed date.
- Year-end clusters. Christmas, Boxing Day, and New Year substitutes can stack up, so a December count that looks like two calendar weeks can stretch several days longer once holidays are excluded.
Which holidays are excluded
The holiday-aware option uses each jurisdiction's official calendar: US federal holidays (OPM), UK bank holidays with separate England & Wales, Scotland, and Northern Ireland calendars (GOV.UK), Canadian federal statutory holidays (Canada.ca), Australian national public holidays (Fair Work Ombudsman), and Uganda's public holidays (Public Holidays Act, Cap 174). You can also supply a custom list of your own organization's holidays. Observance rules differ by jurisdiction: the US moves a Saturday holiday to Friday and a Sunday holiday to Monday; the UK, Canada, and Australia roll forward to the next free weekday; Uganda has no substitution rule, and its Eid dates are included only for years where they have been officially declared (the result warns otherwise).
Counting toward a payment date instead? Net terms like Net 30 normally use calendar days, the invoice due date calculator handles those, and how to count a deadline walks through the wording to watch for.
How we calculate
- Counts whole calendar days, midnight to midnight, in your local timezone.
- Counting is exclusive: today is day 0 and is not counted.
- Business days are Monday–Friday by default (other working weeks are selectable where offered). The holiday-aware result skips public holidays only for the holiday calendar you choose in the calculator: United States, United Kingdom (England & Wales), United Kingdom (Scotland), United Kingdom (Northern Ireland), Ireland, France, Canada, Australia, and Uganda, or your own custom list. There is no default calendar; each result names the one used and lists the excluded days.
- No login and no server: every result is computed in your browser, so you can verify it yourself.
Method and holiday data maintained by Alan Mwine, who works in Linux systems operations, DevOps and security, where time zones, scheduling and exact date arithmetic are daily work.
Sources
- Federal Holidays, U.S. Office of Personnel Management
- UK bank holidays (England & Wales, Scotland, Northern Ireland), GOV.UK
- Public holidays in Ireland (Organisation of Working Time Act 1997, Schedule 2, as amended), Citizens Information Board (Ireland)
- Jours fériés dans le secteur privé (Code du travail, art. L3133-1), Direction de l’information légale et administrative (France)
- Public holidays, Government of Canada
- Public holidays, Fair Work Ombudsman (Australia)
- Public Holidays Act, Cap 174 (Laws of Uganda, Rev. Ed. 2023), ULII / Laws.Africa
- Uganda government annual public holiday lists, Government of Uganda
- Uganda Eid holiday declarations (UMSC moon sighting + Ministry of Public Service), Uganda Muslim Supreme Council / Ministry of Public Service (Uganda)
- ISO 8601, date and time format, ISO
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