How the Working Days Between Dates formula works

Behind the scenes, this calculator walks through every calendar day between your start date and end date, then filters out weekends and any extra holidays you enter. The goal is to match the way most people informally think about “how many workdays do I actually have?”.

• 1. Order the dates: If you accidentally put an end date earlier than the start date, the tool quietly swaps them, so the range always moves forward in time.
• 2. Count calendar days: We measure the total number of calendar days in the range, including both start and end dates.
• 3. Filter by weekday: For each day, we check the weekday number: 0 = Sunday, 6 = Saturday. Anything from 1–5 (Monday–Friday) is treated as a potential working day.
• 4. Remove weekends: Saturday and Sunday are excluded, leaving only weekday counts. This already gives you “weekday days between dates”.
• 5. Subtract holidays: If you know there are public holidays, strike days or office shutdown days inside that range, you can enter the count in the “Public holidays” box. The calculator subtracts them from the weekday total to get your final working days.

In plain English, the calculator does:

Working Days = Weekdays between Start and End − Entered Holidays

In practice, we walk day by day (which is extremely fast on modern browsers) to make sure edge cases like partial weeks, crossing weekends, and very short ranges are all handled correctly.

Examples: how this calculator is used in real life

Here are a few everyday scenarios where a working days calculator is surprisingly useful:

Imagine your last working day is one month from today and your contract says “30 days’ notice”. Plug in your first working day of notice as the start date, your final day in the office as the end date, and subtract any public holidays. You instantly see how many actual workdays you’ll spend handing over your role.

Suppose a client project is due in 6 weeks. Put the project start date and deadline into the calculator and see how many working days you really have — not just how many calendar days. This helps you think in terms of “we only have 27 workdays” instead of “we have a month and a half, plenty of time”.

Parents and students can use this tool to check “how many school days are left until exams?” or “how many weekdays are left in this term?”. Just subtract official school holidays using the holiday box.

Planning a long trip? Enter your first and last day of leave as dates, then see how many working days you’re actually taking off (especially if your leave policy is in working days, not calendar days). This is great for quickly checking how many days of PTO you’ll spend.

Frequently Asked Questions

• Are the start date and end date included?

  Yes. The calculator treats both the start date and the end date as part of the range. If both days are weekdays and you enter zero holidays, a one-day range that falls on a Wednesday will show 1 working day.

• What exactly counts as a “working day” here?

  A working day in this tool is any day from Monday to Friday that is not removed as a public holiday. Saturdays and Sundays are always treated as non-working days for simplicity, even if you sometimes work weekends in real life.

• Does this calculator know my country’s public holidays?

  No. Public holidays vary between countries, regions, and even companies. That’s why there’s a “Public holidays in between” input. You still get a clean business-day count, but with full control over how many holidays to remove.

• Why do my results differ from another website or HR system?

  Different tools apply different rules: some include Fridays only, some treat certain local holidays, half-days or company shutdowns differently. This calculator aims to be simple, transparent and fast — perfect for quick checks, planning, and sharing in chats.

• Can I use this as legal or payroll advice?

  No. Always treat the result as an approximate helper. For anything related to contracts, payroll, or legal notice periods, confirm the official working day calculation with your HR team, accountant, or legal advisor.