About the working days calculator
A working day, or business day, is any day a typical office operates: Monday through Friday, excluding weekends and public holidays. The total calendar days between two dates rarely matches the number of working days, because roughly two in every seven days are weekends and a handful more are holidays. This calculator counts only the weekdays in a date range and can also subtract US federal holidays, giving you the figure that actually drives schedules, pay, and contracts.
Working day counts appear everywhere in professional life. Project plans estimate effort in business days, not calendar days, because no work happens at the weekend. Vacation and paid-time-off accruals are tracked in working days. Service level agreements promise a response "within 3 business days." Payroll, invoice terms (net 30 business days), notice periods, and legal deadlines all hinge on the same count. Getting it right prevents over-promising on a deadline that quietly straddles a long weekend.
The tool counts inclusively, meaning both the start date and the end date are included if they fall on working days. Enter the two dates, choose whether to skip US federal holidays, and it iterates through the range, tallying every Monday-to-Friday and removing any holidays you opted to exclude. Because it runs entirely in your browser, your dates never leave your device.
How it works
The calculation walks through every date from the start to the end, inclusive, and applies two simple tests to each day: is it a weekday, and is it not a holiday? Each day that passes both tests adds one to the running total.
Weekends are identified by the day of the week, so Saturday and Sunday never count. When holiday exclusion is enabled, the tool checks each weekday against the list of US federal holidays for that year and skips any match. Note that when a federal holiday falls on a weekend it is usually observed on the nearest weekday, and that observed date is the one removed from the count.
Worked example
Suppose a project runs from Monday 1 December 2025 to Friday 2 January 2026, and you want working days excluding US federal holidays.
- Calendar span: 1 December to 2 January inclusive is 33 calendar days.
- Remove weekends: that span contains 9 weekend days (Saturdays and Sundays), leaving 24 weekdays.
- Remove holidays: Christmas Day (25 Dec) and New Year's Day (1 Jan) are federal holidays that fall on weekdays, so subtract 2.
- Total: 24 - 2 = 22 working days.
Reference: US federal holidays
The ten US federal holidays the calculator can exclude. When one falls on a weekend, the observed weekday is removed instead.
| Holiday | When it falls |
|---|---|
| New Year's Day | January 1 |
| Martin Luther King Jr. Day | Third Monday in January |
| Presidents' Day | Third Monday in February |
| Memorial Day | Last Monday in May |
| Juneteenth | June 19 |
| Independence Day | July 4 |
| Labor Day | First Monday in September |
| Columbus Day | Second Monday in October |
| Veterans Day | November 11 |
| Thanksgiving / Christmas | Fourth Thursday in November / December 25 |
Common pitfalls
- Confusing calendar days with working days. "Net 30" usually means 30 calendar days, but "within 5 business days" means weekdays only. Read the term before counting.
- Forgetting state and local holidays. The tool covers federal holidays only. Days like Patriots' Day in Massachusetts or Cesar Chavez Day in California are not included; add them manually.
- Assuming a five-day week everywhere. Hospitality, healthcare, and retail often run seven days. Working-day math fits the standard office week, not these sectors.
- Mishandling weekend holidays. A holiday on a Saturday is typically observed the Friday before, and a Sunday holiday the Monday after. Count the observed day, not the calendar date.
- Off-by-one on the endpoints. This calculator counts both endpoints if they are working days. Some contracts exclude the start date, so check which convention applies.
Frequently asked questions
What counts as a working day?
A working day, or business day, is any weekday from Monday to Friday that is not a public holiday. Weekends (Saturday and Sunday) never count, and when holiday exclusion is enabled, US federal holidays are also removed. The result is the number of days a typical office would actually be open within your date range.
Which holidays does the calculator exclude?
When you enable holiday exclusion, it removes the ten US federal holidays: New Year's Day, Martin Luther King Jr. Day, Presidents' Day, Memorial Day, Juneteenth, Independence Day, Labor Day, Columbus Day, Veterans Day, Thanksgiving, and Christmas. State and local holidays such as Patriots' Day are not included, so add one to three days for those if they apply.
Are the start and end dates included in the count?
Yes, the count is inclusive: both the start date and the end date are counted if they fall on working days. If either lands on a weekend or an excluded holiday, it simply does not add to the total. Note that some contracts exclude the start date, so confirm which convention your agreement uses.
What happens when a holiday falls on a weekend?
US federal holidays that land on a Saturday are usually observed on the preceding Friday, and those on a Sunday on the following Monday. The calculator removes the observed weekday, since that is the day offices actually close. This means the holiday only reduces your working-day count when its observed date is a weekday inside your range.
Why are there so many fewer working days than calendar days?
About two of every seven days are weekends, and federal holidays remove several more across a year. Over a long span this adds up quickly: a 33-day stretch over the winter holidays can contain just 22 working days. That is why estimating deadlines or pay in calendar days overstates the productive time available.