How to Calculate Business Day Deadlines and Count Working Days
To find a deadline, enter your start date and the number of working days to add, then click Calculate. The tool counts forward through the calendar, skipping Saturdays and Sundays, and shows the resulting end date. This is the standard method used in project management for sprint planning, SLA calculations, delivery estimates, and contract deadlines where 'business days' are specified.
To count working days between two dates, switch to Day Count mode, enter the start and end date, and click Calculate. The tool counts every weekday (Monday through Friday) in the range, inclusive of the start date and exclusive of the end date (or inclusive of both — you can toggle this). Use this mode to audit how long a task actually took, calculate billable hours in a period, or verify an SLA compliance window.
Why Use This Free Business Day Calculator?
- Adds business days to a start date while correctly skipping weekends
- Day count mode for counting working days between two dates
- Inclusive/exclusive end-date toggle for precise boundary control
- 100% browser-based — your dates never leave your device
- Fast and precise — handles any date range without limitations
- Calculates forward and backward — add days to a date or count days between two dates
- No registration or installation required — works instantly in any modern browser on desktop or mobile
Frequently Asked Questions
Does this tool account for public holidays?
The standard calculation skips Saturdays and Sundays only. It does not account for public holidays by default, because holidays vary by country, region, and even employer. If your project or contract specifies particular holidays as non-working days, you will need to manually add those days to your count or subtract them from the result. Some jurisdictions and contracts define 'business days' to include bank holidays as non-working days — always check the governing definition in your agreement.
When is the start date included in the count?
The start date is typically not counted as a working day — the first working day added is the next business day after the start date. For example, 'deliver within 5 business days starting Monday' means the deadline is the following Monday (Tue=1, Wed=2, Thu=3, Fri=4, Mon=5). However, different industries and contracts have different conventions. The tool includes a toggle for whether to count the start date as day 1 or day 0, so you can match your specific contract language.
What if my start date falls on a weekend?
If you start on a Saturday or Sunday, the tool advances to the next Monday before beginning to count business days. This matches the most common convention: a project that 'starts on a weekend' is practically considered to start on the following Monday. You can override this by checking the 'Allow weekend start dates' option, which keeps the specified date as day 0 and begins counting from there.
How do I calculate an SLA deadline?
An SLA (Service Level Agreement) deadline is typically expressed as a number of business days from an event. To calculate it: enter the event date (e.g., when a support ticket was opened) as the start date, enter the SLA window in business days (e.g., 3 for a 3-day SLA), and click Calculate. The result is the date by which the SLA must be fulfilled. If today is past that date, the SLA has been breached. To convert the resulting dates to Unix timestamps for logging or API calls, use the <a href="/tools/unix-timestamp-converter/">Unix Timestamp Converter</a>. For calculating someone's exact age rather than business days, the <a href="/tools/age-calculator/">Age Calculator</a> handles calendar days with leap year precision.
How are business days defined in legal and financial contexts?
The legal definition of 'business day' varies by jurisdiction. In the United States, the Federal Reserve defines business days as Monday through Friday, excluding federal holidays, for purposes of banking transactions and funds transfer deadlines. The Uniform Commercial Code (UCC) defines a business day as any day other than Saturday, Sunday, or a legal holiday. In the European Union, TARGET2 settlement days exclude weekends and specific EU-wide holidays. Contract law typically defers to the definition in the governing agreement — if the contract doesn't define 'business day,' the jurisdiction's default commercial code applies. Always verify which definition governs your specific situation.
How do I calculate the number of working days in a month or year?
A typical year has 365 days, of which 104 are weekend days (52 Saturdays + 52 Sundays), leaving approximately 261 working days before subtracting public holidays. A leap year has 262 weekdays if the extra day falls on a weekday. Most months contain 21-23 working days: months with 31 calendar days have 22-23 weekdays, months with 30 days have 21-22, and February has 20 weekdays (20-21 in a leap year). Use Day Count mode with the first and last day of the month or year to get the exact count for any specific period, accounting for which days of the week the month starts and ends on.
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