Workdays Calculator – Count Business Days Between Dates

About the Workdays Calculator

This calculator works in two directions. Duration mode counts how many working days fall between two dates. Add or Subtract mode takes a starting date and a number of workdays and tells you which date you land on. Both modes let you define what counts as a working day, including which weekdays to exclude and whether to skip public holidays.

Working days matter because almost nothing in business runs on calendar days. Payment terms, notice periods, statutory deadlines, shipping estimates, and service level agreements are written in business days precisely because weekends and holidays are not working time. The gap between the two counts is larger than people expect: weekends alone remove about 28% of any long span, so a “30 business day” commitment is roughly six calendar weeks, not four. As a rough sanity check, \text{workdays} \approx \text{calendar days} \times \frac{5}{7} before holidays are subtracted.

The customizable weekend is the part that makes this usable outside the US and Europe. The Monday-to-Friday week is far from universal: much of the Middle East runs Sunday to Thursday, several countries treat Saturday as a working day, and plenty of businesses operate six-day weeks. The Custom Selection option lets you tick exactly which days are non-working rather than forcing you into an assumption that does not match your calendar.

One honest limitation worth knowing before you rely on it: the built-in holiday list covers US federal holidays. If you are calculating against a different country’s calendar, use Weekends Only and subtract your own public holidays from the result, because the tool’s holiday dates will not match yours.

The BigToolSite team that looks after the date and time tools tested both modes across year boundaries, leap years, reversed date pairs, every exclusion setting, and custom weekend definitions, confirming that each day in the range is evaluated individually rather than approximated from a weekly average.

When you need the total calendar span alongside the working-day count, the Date Difference Calculator breaks the same period into years, months, weeks, and hours.

For adding calendar time rather than working time — three months, six weeks — the Date Calculator handles that arithmetic and supports custom holiday entries.

Once you have your deadline date, the Countdown Timer turns it into a live countdown you can watch tick down.

How to Use the Workdays Calculator

• Pick a Calculation Mode. Duration counts workdays between two dates. Add / Subtract Days finds a date a set number of workdays away.
• In Duration mode, set both a Start Date and an End Date. If you enter them backward, they are swapped automatically and the result says so.
• In Add / Subtract mode, set the Start Date, choose Add or Subtract, and enter the number of workdays.
• Tick Include end date when every date in the range counts as a day, such as billable days or days of leave. Leave it unticked when measuring a gap.
• Choose what to exclude: Weekends and Public Holidays, Weekends Only, Public Holidays Only, or Custom Selection.
• With Custom Selection, tick each day of the week that is not a working day for you. Saturday and Sunday are ticked by default. A separate checkbox controls whether public holidays are also skipped.
• Click Calculate.
• Duration mode returns the workday count plus the total calendar days. Add / Subtract mode returns the resulting date with its day of the week, plus how many calendar days were spanned to get there.

Example Usage

Duration mode: March 2, 2026 to April 30, 2026, excluding weekends and public holidays

Result: 43 workdays across 59 total calendar days

The 16-day difference is eight weekends plus any holidays in the range. That gap is exactly why quoting a project in calendar weeks and delivering in working days causes so many missed expectations.

Add / Subtract mode: start June 1, 2026, add 20 workdays, excluding weekends and holidays

Result: the date four working weeks later, with the weekday shown so you can see immediately whether it lands somewhere awkward

Subtraction is the more useful direction for planning. To find the latest date you can start a piece of work due on a fixed deadline, set the deadline as your start date, choose Subtract, and enter the working days the task needs. The answer is your real drop-dead start date.

For a Sunday-to-Thursday working week, choose Custom Selection and tick Friday and Saturday as the excluded days, leaving Sunday unticked. The count then reflects your actual week rather than a Western default.

Frequently Asked Questions