Business Days Calculator
Free work days calculator that counts business days between two dates. Exclude weekends and US or UK public holidays automatically.
This work days calculator counts the number of business days (Monday through Friday) between any two dates. It automatically excludes weekends and optionally subtracts US federal holidays or UK bank holidays. The result includes total calendar days, working days, weekend days, and a visual calendar strip for ranges up to 90 days.
About Business Days Calculator
How Business Days Are Counted
The calculator iterates through each day in the date range and counts only Monday through Friday. Weekends (Saturday and Sunday) are excluded. If you select a holiday preset, any public holiday that falls on a weekday is also excluded from the count.
| Output | What It Shows | Example (Jan 1 - Jan 31, no holidays) |
|---|---|---|
| Calendar days | Total days in the range including weekends | 31 days |
| Working days | Monday-Friday count minus holidays | 23 working days (in a typical month) |
| Weekend days | Saturdays and Sundays in the range | 8 weekend days |
| Holidays excluded | Public holidays that fell on weekdays | 1 (New Year's Day) |
| Weeks + days | Calendar days broken into full weeks plus remaining days | 4w 3d |
Holiday Presets
| Preset | Number of Holidays | Included Holidays |
|---|---|---|
| None | 0 | Weekends only - no public holidays excluded |
| US Federal | 11 | New Year's Day, MLK Day, Presidents' Day, Memorial Day, Juneteenth, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving, Christmas |
| UK Bank Holidays | 8 | New Year's Day, Good Friday, Easter Monday, Early May, Spring Bank, Summer Bank, Christmas Day, Boxing Day |
When a holiday falls on a weekend, the observed date (usually the following Monday) is used instead. The calculator handles this automatically for both US and UK presets.
Working Days Per Month Reference
The number of working days varies by month depending on how weekends fall:
| Calendar Days | Min Working Days | Max Working Days | Average |
|---|---|---|---|
| 28 (February, non-leap) | 20 | 20 | 20 |
| 29 (February, leap) | 20 | 21 | 20.4 |
| 30 (April, June, Sept, Nov) | 20 | 22 | 21.4 |
| 31 (Jan, Mar, May, Jul, Aug, Oct, Dec) | 21 | 23 | 22.1 |
A typical year has 260-262 working days before holidays. After subtracting 8-11 public holidays (depending on country), the effective working days in a year are usually 249-252.
Common Use Cases
| Scenario | How Working Days Helps |
|---|---|
| Project planning | Estimate how many working days a task will take and find the expected completion date |
| Contract deadlines | Legal contracts often specify "business days" - count them accurately to avoid penalties |
| Shipping estimates | "5-7 business days" excludes weekends - the calendar equivalent might be 7-10 days |
| Notice periods | Employment notice periods (e.g. "30 business days") need exact counts |
| SLA calculations | Service level agreements measured in business days need precise tracking |
| Payroll periods | Count working days in a pay period to calculate daily-rate contractor pay |
| School calendars | Count instructional days between term dates |
Visual Calendar Strip
For date ranges of 90 days or fewer, the calculator displays a colour-coded strip where each day is a small square:
| Colour | Meaning |
|---|---|
| Green | Working day (Monday-Friday, not a holiday) |
| Grey | Weekend (Saturday or Sunday) |
| Amber | Public holiday falling on a weekday |
Hover over any square to see the full date. This visual makes it easy to spot clusters of non-working days (like holiday weekends) and understand the pattern of your date range.
Business Days vs Calendar Days
| Calendar Days | Approx. Business Days | Quick Estimate |
|---|---|---|
| 7 | 5 | 1 week = 5 working days |
| 14 | 10 | 2 weeks = 10 working days |
| 30 | 21-22 | Roughly 70% of calendar days |
| 60 | 42-44 | Two months of working days |
| 90 | 63-65 | One quarter of working days |
| 365 | 260-262 | Full year before holidays |
A quick rule of thumb: multiply calendar days by 5/7 (approximately 0.714) to estimate business days. This does not account for holidays, so the actual count may be 1-3 fewer per month.
For a pure date difference without the business-day focus, the date difference calculator counts total calendar days between two dates. To calculate hours worked within those days, the hours calculator handles clock-in and clock-out times. All calculations run in your browser.
How Substitute Holiday Days Work
When a public holiday falls on a weekend, it is usually observed on an adjacent weekday so workers still get the day off. This calculator applies the official US and UK substitute-day rules, which matter because the observed date is the one that reduces the working-day count.
- US federal rule (5 U.S.C. 6103): a holiday falling on a Saturday is observed on the preceding Friday; a holiday on Sunday is observed on the following Monday. The Office of Personnel Management (OPM) publishes the annual observed dates.
- UK bank holiday rule: a bank holiday that lands on Saturday or Sunday is observed on the next non-bank-holiday weekday. Because Christmas Day (25 Dec) and Boxing Day (26 Dec) are adjacent, this can push Boxing Day out to Tuesday when Christmas Day itself gets bumped.
In 2026, for example, Independence Day (4 July) is a Saturday, so federal offices close on Friday 3 July. In the UK, Boxing Day 2026 falls on a Saturday, so the substitute bank holiday is Monday 28 December. Selecting "US Public Holidays" or "UK Bank Holidays" in the calculator applies these rules automatically for every year in the date range.
Worked Example: A Two-Month Project Deadline
Say a project kicks off on 6 April 2026 (the Monday after the Easter weekend in England and Wales) with an eight-week schedule. Counting calendar days from 6 April to 31 May gives 56 days. Of those, 16 are weekends, leaving 40 weekdays. With the UK bank holiday preset, Early May bank holiday (4 May) and Spring bank holiday (25 May) both fall on Mondays inside the range and reduce working days by two, giving 38 working days. That is about 32% fewer than the naive eight-week figure of 40, which is why project managers using calendar weeks without subtracting bank holidays often slip deadlines in the spring.
Running the same 56-day span under the US federal preset gives 40 working days, because no US federal holidays fall in that window in 2026. The same calendar range therefore has two extra working days on a US schedule compared with a UK schedule - a useful cross-check for teams working across both countries.
Why Working-Day Counts Vary Year to Year
A standard Gregorian year contains 365 days (366 in a leap year), which divides into 52 complete weeks plus one or two leftover days. Because the leftover days can land on any weekday, the number of Monday-to-Friday workdays in a year ranges from 260 to 262 before holidays are subtracted. The US Bureau of Labor Statistics uses 260 as its default establishment-survey reference for non-leap years.
| Year | Type | Weekdays | US Federal Holidays on Weekdays | Effective Working Days (US) |
|---|---|---|---|---|
| 2024 | Leap | 262 | 11 | 251 |
| 2025 | Standard | 261 | 10 | 251 |
| 2026 | Standard | 261 | 10 (Independence Day observed on Friday 3 July) | 251 |
| 2027 | Standard | 260 | 10 | 250 |
| 2028 | Leap | 261 | 10 | 251 |
Most payroll departments budget 250-252 working days per year for full-time salaried staff. Daily-rate contractors and locum workers often use 252 as the divisor for converting an annual salary into a day rate, because 252 is the long-run average working-day count across the US and UK calendars.
Business Days in Law and Contracts
Contract drafters rely on the difference between "calendar days" and "business days" to set realistic deadlines. A "5 business days" notice is not the same as five calendar days, and misreading the phrasing can invalidate a filing.
- English contract law: unless the contract defines the term, a "business day" generally means any day other than a Saturday, Sunday, or a bank holiday in England and Wales. The Law Society's standard conditions of sale (5th edition) use this exact wording.
- US civil procedure: Federal Rule of Civil Procedure 6(a) says that when a period is stated in days less than 11, intermediate Saturdays, Sundays, and legal holidays are excluded. The Supreme Court confirmed in Burnett v. New York Central R. Co. (1965) that a deadline falling on a legal holiday rolls to the next working day.
- UCC contract deadlines: under Uniform Commercial Code section 1-302, deadlines denominated in business days run only on days when banks are open for substantially all banking functions in the relevant state.
- EU consumer rights: the 14-day cooling-off period in the Consumer Rights Directive (2011/83/EU) is measured in calendar days, not business days - a common source of confusion for UK and EU e-commerce teams.
Working Days Across Major Economies
Different countries use different definitions of a public holiday, which affects effective working-day counts for international SLAs and shipping estimates.
| Country | Typical Weekly Work Pattern | Public Holidays Per Year | Approx. Working Days |
|---|---|---|---|
| United States | Mon-Fri | 11 federal (state holidays vary) | 250-252 |
| United Kingdom (Eng/Wales) | Mon-Fri | 8 bank holidays | 252-253 |
| United Kingdom (Scotland) | Mon-Fri | 9 bank holidays | 251-252 |
| Australia | Mon-Fri | 7-13 (state variation) | 248-253 |
| Germany | Mon-Fri | 9-13 (state variation) | 248-252 |
| France | Mon-Fri | 11 national | 250 |
| Japan | Mon-Fri | 16 (highest in OECD) | 245 |
| UAE / Saudi Arabia | Sun-Thu | Varies | ~250 |
Saudi Arabia moved to a Sunday-Thursday working week in 2013 and the UAE shifted to a Monday-Friday week (with a half-day Friday) in January 2022, which changed how weekend days are counted for any cross-border deadline that touches the Gulf.
Common Mistakes When Counting Business Days
- Counting the start date twice. Most legal frameworks exclude the day of the triggering event and start the clock on the next business day. Rule 6(a) of the Federal Rules of Civil Procedure is explicit: do not count the day of the event.
- Forgetting the substitute day. If a fixed-date holiday falls on a weekend, the observed date is the one that closes offices. This calculator shifts US and UK holidays accordingly so the working-day total matches real office closures.
- Mixing calendar weeks with business weeks. "Two weeks" sometimes means 14 calendar days (the literal reading) and sometimes means 10 business days (the office-culture reading). Spell it out in contracts to avoid disputes.
- Ignoring regional variations. Scotland observes the 2 January holiday that England and Wales do not. Northern Ireland adds St Patrick's Day and the Battle of the Boyne. If a UK-wide SLA uses "UK bank holidays" without qualifying the region, the effective working-day count can differ by three days a year.
- Assuming the calendar is symmetrical. Q1 typically has the fewest working days (62-63) because of Martin Luther King Jr. Day and Presidents Day in the US, or Easter and the May bank holiday cluster in the UK. Q4 has the fewest working days when Christmas Eve and Boxing Day land mid-week.
Sources
- GOV.UK - UK Bank Holidays (England, Wales, Scotland, Northern Ireland)
- US Office of Personnel Management - Federal Holidays
- 5 U.S.C. 6103 - Holidays (Cornell Law)
- Federal Rules of Civil Procedure, Rule 6 - Computing Time
- US Bureau of Labor Statistics - Employment Reference Periods
- EU Consumer Rights Directive 2011/83/EU
Frequently Asked Questions
How are working days calculated?
Working days are Monday through Friday. The calculator counts all days in your date range, subtracts weekends (Saturday and Sunday), and optionally subtracts public holidays that fall on weekdays.
Which holidays are included?
You can choose US public holidays (11 federal holidays) or UK bank holidays (8 standard bank holidays including Good Friday, Easter Monday, and the spring/summer bank holidays). Select "None" to count all weekdays without holiday exclusions.
Does it handle different years correctly?
Yes. If your date range spans multiple years, the calculator includes the correct holidays for each year. Moveable holidays like Easter and Thanksgiving are computed for each year in the range.
What is the calendar strip view?
For date ranges of 90 days or fewer, the calculator shows a visual strip where each day is a small coloured square. Green squares are working days, grey are weekends, and amber are holidays. This makes it easy to see the pattern at a glance.
What does the "weeks and days" breakdown show?
It divides the total number of calendar days into complete weeks and remaining days. For example, 17 days would show as "2w 3d" meaning 2 full weeks plus 3 extra days.
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