Calendar days include every day from Monday through Sunday. Business days generally include working days and exclude weekends, while public holidays may also be excluded depending on the country, organisation, or agreement. A weekday count is not always identical to a true business-day count.
Enter two dates to calculate exact years, months, weeks, days, weekdays, weekends, and inclusive date counts.
Holiday rules can create another difference between a weekday count and an official business-day count.
What Are Calendar Days?
Calendar days include every date on the calendar.
Mondays, weekends, and public holidays are all included.
The Date Difference Calculator reports total calendar days separately from weekdays.
What Are Business Days?
Business days are days on which ordinary business operations are expected to occur.
They commonly run from Monday through Friday.
Official holidays may also be excluded, but the exact definition depends on location and context.
Calendar Days vs Weekdays vs Business Days
Calendar days include the entire week.
Weekdays generally include Monday through Friday without checking holidays.
Business days may exclude both weekends and recognised holidays.
| Count type | Includes weekends? | Excludes holidays? |
|---|---|---|
| Calendar days | No weekends are excluded | No |
| Weekdays | Yes, weekends are excluded | Not automatically |
| Business days | Usually excluded | Often, according to a holiday calendar |
Worked One-Week Example
Consider a period from Monday through the following Sunday.
The inclusive calendar count is seven days.
The period normally contains five weekdays and two weekend days.
How Public Holidays Change the Result
A weekday can still be a non-working day when it is an official holiday.
A seven-day period containing a Monday holiday may have only four business days.
Holiday calendars differ between countries, regions, industries, and organisations.
Why a Calculator May Report Weekdays Instead
A general date calculator can identify Saturdays and Sundays from the calendar.
It cannot identify every applicable public holiday without knowing the location and holiday rules.
For this reason, a weekday total should not automatically be described as a definitive business-day total.
Inclusive and Exclusive Counting
Day counts can include or exclude the boundary dates.
A deadline described as five business days after Monday normally begins counting after Monday unless the rules say otherwise.
Always confirm whether the starting date is included.
Business Days for Deadlines
Contracts, deliveries, payment terms, and response periods may use business-day deadlines.
The written definition in the relevant policy or agreement controls the count.
Do not assume that all organisations use the same weekend and holiday rules.
Countries with Different Working Weeks
Not every country or organisation follows a Monday-to-Friday working week.
Some workplaces use different weekend days or operate six days per week.
A business-day calculation must reflect the applicable schedule.
How to Count Weekdays Manually
List the dates in the interval and identify their days of the week.
Remove Saturdays and Sundays when using a standard Monday-to-Friday schedule.
Then remove applicable holidays to produce a business-day count.
- 1Choose the counting boundaries
Decide whether the first and last dates are included.
- 2Exclude weekend dates
Remove the weekend days used by the applicable work schedule.
- 3Exclude recognised holidays
Apply the official holiday calendar for the relevant location.
Calendar Days for Ordinary Durations
Calendar-day calculations are useful when every elapsed day matters.
Examples include age-like intervals, accommodation periods, subscriptions, and general date differences.
Weekends and holidays remain part of the elapsed duration.
Common Mistakes
Do not use weekday and business-day counts as interchangeable terms without checking holidays.
Do not assume that every location uses Saturday and Sunday as its weekend.
Do not overlook inclusive and exclusive counting rules.
Do not apply one country's holiday calendar to another location.
Conclusion
Calendar days include every date, while weekdays normally exclude weekends.
A true business-day count may also exclude recognised holidays.
Use the Date Difference Calculator to compare calendar days, weekdays, and weekend days.
FAQs
What is the difference between calendar and business days?
Calendar days include every date, while business days usually exclude weekends and holidays.
Are weekdays the same as business days?
Not always. A weekday may be an official holiday.
How many business days are in a normal week?
A Monday-to-Friday schedule normally contains five, before holidays are considered.
Are Saturdays and Sundays calendar days?
Yes. Every date on the calendar is a calendar day.
Do all countries use the same business week?
No. Working weeks and weekend days can vary.