Business Days Calculator

What this tool does

Business Days Calculator counts Monday-to-Friday working days between a start and end date, excluding weekends and any holiday dates you list, or alternatively adds (or subtracts) a chosen number of business days to a starting date, skipping weekends and holidays along the way.

Project deadlines, shipping estimates and payment terms are almost always quoted in business days rather than calendar days, but working out the real calendar date that corresponds to "10 business days from now" means mentally skipping every Saturday, Sunday and public holiday along the way, which gets error-prone fast over longer spans.

This calculator handles both directions of that problem: counting how many business days fall between two given dates, or starting from a date and adding (or subtracting) a chosen number of business days to land on a real calendar date. Both calculations let you list specific holiday dates to exclude, so a company-specific or regional holiday calendar is accounted for rather than just weekends.

How to use Business Days Calculator

1. Choose Count business days between two dates or Add business days to a start date.
2. For counting, enter the Start date and End date, and choose whether to include both end dates.
3. For adding, enter the Start date and the number of business days to add (negative to subtract).
4. Optionally list Holiday dates to exclude, one per line in YYYY-MM-DD format.
5. Read the resulting business day count, or the resulting calendar date.

Tips for better results

• Holiday dates that fall on a weekend don’t change the count, since they were already excluded as weekends; only holidays that fall on a weekday actually reduce the business day total.
• For "add business days" calculations, a listed holiday is simply skipped over like a weekend, so the resulting date will never land on one of your listed holidays.
• Toggle Include both start and end date off if you specifically want the count strictly between two dates, excluding both endpoints.
• Maintain a reusable holiday list for your country or company and paste it in each time for consistent results across calculations.

Common use cases

• Calculating a realistic delivery or project deadline a set number of working days from today.
• Working out how many business days of notice, processing time or payment terms fall between two dates.
• Excluding public holidays from a working-day count for payroll or SLA calculations.
• Checking whether a quoted "5-10 business days" shipping estimate lines up with a specific calendar delivery window.

Common mistakes to avoid

• Forgetting to list relevant holidays, which causes the business day count to overstate actual working days whenever a holiday falls on a weekday within the range.
• Assuming "business days" automatically excludes your organisation’s specific holidays without listing them; only weekends are excluded by default.
• Mixing up the inclusive toggle’s effect, which changes whether the start and end date themselves count toward the total.