Business Days Calculator — Count, Add & Subtract Working Days

When a fixed-date holiday falls on a weekend, many countries "observe" it on the nearest weekday instead — so the holiday still results in a day off even though it technically falls on a day that isn't a working day. In the US federal holiday system: if a holiday falls on Saturday, it's observed on Friday; if it falls on Sunday, it's observed on Monday. For example, if Independence Day (July 4th) falls on a Saturday, Friday July 3rd is the observed federal holiday. This tool's US holiday set calculates observed dates dynamically for every year, so it always applies the correct observed date regardless of which year you're calculating. UK, CA, AU, and EU holiday sets also apply standard observed-date rules. If your organization doesn't observe a particular holiday, simply uncheck it in the holiday list.

Net 30 calendar days simply means 30 days from the invoice date, including weekends and holidays. Net 30 business days means 30 working days (Monday–Friday, excluding holidays). The difference can be significant: a 30-business-day period typically spans 6–7 calendar weeks, or roughly 42–49 calendar days depending on weekends and holidays in that window. Most payment terms in US and UK contracts use calendar days unless specifically stated as "business days." Legal deadlines, SLA contracts, and some invoice terms do specify business days — always check your contract. This calculator's Add mode handles both interpretations: toggle holidays off to count purely by workweek, or include your region's holidays for a full business-day count.

Yes — this is one of the unique features of this tool. The workweek selector lets you click any combination of the 7 day buttons. Use the quick preset buttons: Mon–Fri (standard 5-day Western workweek), Mon–Sat (common in retail, construction, and healthcare), Sun–Thu (standard in many Middle Eastern countries including Saudi Arabia, UAE, and Egypt, where the weekend is Friday–Saturday), or Sat–Thu. You can also create any custom pattern by clicking individual day buttons. The calculation automatically uses your selected working days as the definition of "business days" throughout, including when determining which days holidays are observed on.

Switch to the "Add Business Days" mode. Enter the date the SLA started (e.g., when a support ticket was opened) as the start date. Enter your SLA window in business days (e.g., 2 for a 2-business-day response SLA). The tool will show you the deadline date, skipping weekends and any holidays you've configured. For example, if a ticket opens on Friday and your SLA is 2 business days, the deadline would be Tuesday (Monday = day 1, Tuesday = day 2) — not Sunday. To verify compliance for an existing ticket, use Count Between Dates mode with the open date and close date to see how many business days elapsed. Compare that to your SLA to determine if the response was on time.

Several factors can cause differences: (1) Start/end date inclusion — some tools count the start date as day 1 (inclusive), others start counting from the day after. This tool has explicit "Include start date" and "Include end date" toggles so you can match your organization's convention. (2) Observed holidays — tools that use fixed holiday dates (e.g., always July 4th) without adjusting for weekend observance will count different days than tools that apply the observed-date rule. (3) Holiday set — different tools include different holidays. This tool shows each holiday individually by name so you can see exactly which are included and deselect any that don't apply to your organization. (4) Custom workweek — if your organization counts Saturday as a working day, the count will be higher than tools that assume Mon–Fri only.