📅 Date & Time
How to Count Working Days Between Two Dates
Why business days matter for deadlines and pay, how to count Monday-to-Friday days between two dates, and why public holidays need handling separately.
Updated 21 September 2026 · 2 min read
Plenty of deadlines are set in working days, not calendar days — a "payment within 5 business days" clause, a notice period, or a project estimate. Because weekends don't count, the calendar gap and the working-day gap can differ by a lot, and guessing rarely ends well.
What counts as a working day
A working day, or business day, is any weekday — Monday to Friday. Saturdays and Sundays are excluded. Counting them by hand means walking the calendar and skipping every weekend, which is fine over a week but error-prone across a month or a quarter.
A quick worked example
Suppose a task runs from a Monday to the Friday of the following week. That's 12 calendar days end to end. But two Saturdays and two Sundays fall inside, so you subtract four weekend days: 8 working days, counting both endpoints. The calculator reports the total days, working days and weekend days together so you can see exactly where the difference comes from.
Don't forget public holidays
A pure weekday count doesn't know about bank holidays, and those genuinely reduce the working days available. They're deliberately left out here because holidays vary by country, region and year — a UK bank holiday isn't a US federal holiday, and neither lines up with the calendar elsewhere.
- Count the plain working days between your dates first.
- List any public holidays that fall on a weekday within the range.
- Subtract those from the total to get true business days.
The working days calculator handles the weekday counting for you, including both endpoints, so you only need to knock off the holidays that apply to your country. For the plain gap in every unit — years, months, weeks and days — the date difference calculator and its companion guide are the tools to reach for, and the days-alive breakdown is a fun example of the same date maths.
Frequently asked questions
- Does the count include the start and end dates?
- Yes. This calculator counts inclusively, so both the start date and the end date are part of the total if they fall on weekdays. A single Monday-to-Friday span therefore comes to 5 working days.
- Are public holidays excluded?
- No. It excludes weekends — Saturdays and Sundays — but not public holidays, because those differ by country and region. Count the weekday total first, then subtract any holidays that apply to you.
- What's the difference between calendar days and working days?
- Calendar days count every day including weekends; working days count only Monday to Friday. Over a full week that's 7 versus 5, and the gap grows the longer the period you're measuring.