Add Weekdays Calculator
Deadlines stated in business days need weekend-aware arithmetic, because counting plain calendar days can land you on a Saturday when offices are shut. This calculator adds a number of weekdays to a start date, stepping forward one day at a time and counting only Monday to Friday, and tells you the resulting date and its day of the week. Enter a negative number to count backwards, which is handy for finding the latest start date that still meets a deadline. It skips weekends only; public holidays vary by location, so add extra weekdays if your deadline must clear them too.
Add weekdays method
step one calendar day at a time from the start date
count a day only if it is Monday to Friday
stop when the weekday count reaches the requested number
forward for positive input, backward for negative
calendar days spanned = total days stepped
Because weekends are skipped, the number of calendar days spanned is usually larger than the weekday count: each full working week of 5 weekdays spans 7 calendar days. Weekend days skipped is the difference between the two.
Add weekdays notes
- Only Saturdays and Sundays are skipped, not public holidays.
- Use a negative value to find an earlier deadline.
- Five weekdays typically span seven calendar days.
- For holiday-aware deadlines, add extra weekdays to compensate.
- The federal holiday list is published by the Office of Personnel Management.
Add weekdays: frequently asked questions
How does adding weekdays work?
Starting from your date, the calculator steps forward one calendar day at a time, counting only Monday to Friday, until it has counted the number of weekdays you asked for. Weekends are skipped, so adding 5 weekdays to a Monday lands on the following Monday.
Can I subtract weekdays?
Yes. Enter a negative number to count backwards. The calculator steps to earlier dates, again skipping weekends, which is useful for working out the latest start date that still meets a deadline a set number of business days away.
What happens if the start date is a weekend?
Counting begins from the day after the start date for forward additions, so a start on Saturday or Sunday does not itself count as a weekday. The first weekday found becomes weekday number one, ensuring the count reflects actual working days.
Does it account for public holidays?
No. This calculator skips only weekends, not public holidays, because holiday calendars differ by country, state, and employer. If your deadline must also skip holidays, add extra weekdays to compensate, or check the federal holiday list from the Office of Personnel Management.
Why count business days instead of calendar days?
Contracts, shipping promises, and legal deadlines are often expressed in business days so they do not count weekends when offices are closed. Counting weekdays gives a realistic working deadline rather than one that lands on a Saturday or Sunday.
Official sources
- U.S. Office of Personnel Management: Federal Holidays.
- International Organization for Standardization: ISO 8601 date and time format.
Reviewed by the CalculatorHub team, edited by James Graham, 17 June 2026. See our methodology.