Quick answer

To calculate business days, count the days between two dates and skip any days that are not normal workdays. In most cases, that means skipping Saturdays and Sundays. If needed, also subtract any company holidays or public holidays.

Simple business day idea:
Count all weekdays between the start date and end date, then remove holidays if they apply.

Business days usually mean

Monday through Friday, excluding weekends and sometimes excluding holidays.

Calendar days mean

Every day on the calendar, including weekends and holidays.

In this guide

What business days mean

A business day is usually a standard workday. For many people and organizations, that means:

  • Monday
  • Tuesday
  • Wednesday
  • Thursday
  • Friday

Saturdays and Sundays are usually not counted as business days. Some workplaces also remove holidays from the total. That is why “5 business days” and “5 calendar days” are often very different.

Basic way to calculate business days

The easiest manual method is:

  1. Write down the start date and end date.
  2. Count only the weekdays between them.
  3. Skip Saturdays and Sundays.
  4. Subtract any holidays if your situation requires that.
Simple rule:
If a day falls on a weekend, do not count it as a business day.

This works well for short ranges. For larger ranges, a calculator is faster and reduces mistakes.

Worked example

Suppose you want to know the number of business days from Monday, June 3 to Friday, June 14.

  • Week 1: Monday through Friday = 5 business days
  • Weekend: Saturday and Sunday = 0 business days
  • Week 2: Monday through Friday = 5 business days

Total: 10 business days.

Example result:
12 calendar days can still equal only 10 business days once the weekend is removed.

How holidays affect the count

Holidays can reduce the total even more. If one holiday falls on a weekday inside your date range, subtract that day from the business day count.

For example, if a range includes 10 weekdays but one of those weekdays is a holiday, the adjusted result becomes:

10 weekdays − 1 holiday = 9 business days

Keep in mind that holiday rules vary. A bank, court, school, and private employer may all use different holiday calendars.

Inclusive vs exclusive counting

One common source of confusion is whether the start date counts.

Exclusive counting

Usually starts counting after the start date.

Inclusive counting

Counts both the start date and the end date if they qualify.

This matters for deadlines, shipping windows, payroll timing, legal notices, and project planning. Always check which method your workplace or form is using.

Common mistakes

  • Counting calendar days instead of business days
  • Forgetting to remove a holiday
  • Including weekends by accident
  • Counting the start date when the rule says not to
  • Assuming every business follows the same holiday schedule
Good habit:
If the result matters for work, contracts, payroll, or deadlines, double-check whether holidays and the start date should count.

When to use business days vs calendar days

Use business days for

Shipping estimates, approval timelines, office workflows, banking, and legal or HR deadlines.

Use calendar days for

Trips, vacations, countdowns, birthdays, subscriptions, and general elapsed time.

A date difference calculator tells you the raw number of days. A business day calculator goes one step further and removes non-working days.

Bottom line

To calculate business days, count only the weekdays in the range and subtract any holidays that matter for your situation. That gives you a more realistic measure of working time than simple calendar days.

Business days = weekdays − applicable holidays

Related tools: Date Difference Calculator · Days Until Calculator