Getting the number of working days right is critical when calculating pay, planning rotas, or managing projects. Yet many UK employers still rely on guesswork or outdated manual methods, increasing the risk of errors. Whether you're calculating the number of working days between two dates for payroll or using Excel to forecast project deadlines, accuracy is key.
In this article, we explore how to calculate working days in the UK.
We’ll show you how to account for weekends, public holidays and regional variations, so you can make decisions based on reliable timelines.
Key takeaways
- Learn how to manually count working days and adjust for weekends and bank holidays
- Master Excel functions like NETWORKDAYS, NETWORKDAYS.INTL and WORKDAY with UK holiday lists
- Discover how accurate working day counts support payroll, staff planning and project scheduling
How to calculate working days in the UK?
In the UK, workdays are shaped by weekends and public holidays, which vary by region between England, Wales, Scotland and Northern Ireland. Understanding these differences is crucial for accurate scheduling, payroll and compliance.
Defining working days in the UK
In the UK, a standard working day typically refers to Monday to Friday, excluding weekends and public holidays. However, depending on your sector and employment contracts, definitions may vary. For legal and payroll purposes, it’s essential to follow the statutory calendar applicable to your business location.
Excluding weekends and bank holidays
The simplest working day calculation excludes Saturdays and Sundays. But UK-specific public holidays must also be removed from the total. These include national holidays like Christmas and Easter, as well as region-specific days such as St Andrew’s Day in Scotland or the Battle of the Boyne holiday in Northern Ireland.
Failing to adjust for these dates can lead to payroll miscalculations, delayed deliverables, or rota issues.
Adjustments for England, Wales, Scotland, Northern Ireland
Bank holidays aren’t the same across the UK. For example:
- Scotland has an extra day after New Year’s Day (2nd January), and St Andrew’s Day
- Northern Ireland observes St Patrick’s Day and the Twelfth of July
- England and Wales follow a shared calendar, but don’t include these regional days
Kelio’s solution accounts for all these distinctions automatically, ensuring your calculations reflect local variations, no manual adjustments required.
Calculating working days manually
While automated tools simplify the process, it’s still useful to understand how to calculate working days manually, especially for quick estimates or spreadsheet-based audits.
Counting weekdays between two dates
To count working days manually, start by calculating the total number of days between two dates, then subtract all weekends. For example, between Monday 1st July and Friday 12th July 2025, there are 12 calendar days and 8 working days (excluding two weekends).
This method works for short time frames, but it becomes unreliable when public holidays fall within the period.
Factoring in UK bank holidays
Once you’ve excluded weekends, review the public holiday calendar for the relevant region. Each holiday that falls on a weekday within your selected date range must be subtracted to ensure accuracy.
Example: If a bank holiday falls on a Monday within your range, you’ll need to deduct that day from your working day total. Be aware that substitute days apply when holidays fall on weekends.
Using Excel to calculate working days
Excel offers several powerful functions to calculate working days, especially when you need repeatable formulas or integrate date logic into payroll or project plans. Let’s explore the most effective ones for UK use.
NETWORKDAYS explained
The =NETWORKDAYS(start_date, end_date) formula counts the number of working days between two dates, automatically excluding weekends. However, it assumes Saturday and Sunday are non-working days and doesn’t account for bank holidays unless you provide them as a separate list.
To improve accuracy, include a list of UK bank holidays and reference it as follows :
=NETWORKDAYS(A1, A2, B1:B10)
Where:
- A1 and A2 are your start and end dates
- B1:B10 is your list of public holidays
NETWORKDAYS.INTL with UK bank holidays
For more control over which days are treated as weekends, use =NETWORKDAYS.INTL. This function allows you to customise which days are excluded. It’s particularly useful if your business week is non-standard or your operations include weekends.
Syntax:
=NETWORKDAYS.INTL(start_date, end_date, weekend, [holidays])
Example:
=NETWORKDAYS.INTL(A1, A2, "0000011", B1:B10)
This excludes only Saturday and Sunday (last two digits), while keeping Monday to Friday active.
WORKDAY functions for forward planning
Need to calculate a future date after a set number of working days? Use =WORKDAY(start_date, days, [holidays]). This is ideal for deadlines, delivery windows, or project timelines.
Example:
=WORKDAY(TODAY(), 10, B1:B10) gives you the date 10 working days from today, excluding weekends and any listed holidays.
Practical Excel examples
Scenario: You want to know how many working days fall between 1st May and 31st May 2025, excluding UK bank holidays.
- Input your start and end dates in A1 and A2
- List May bank holidays in B1:B3 (e.g., Early May Bank Holiday, Spring Bank Holiday)
- Use: =NETWORKDAYS(A1, A2, B1:B3)
This formula delivers an accurate count of business days, far more reliable than subtracting weekends manually.
Business applications of a working days calculator
Knowing exactly how many working days fall between two dates can streamline decision-making across your organisation. Here’s how Kelio’s solution supports your role, whether you're in HR, operations, finance or general management.
For payroll and HR administrators
The number of weekdays between two dates affects payroll, leave and statutory pay accuracy.
Kelio helps you:
- Validate payroll cut-off dates with precision
- Pro-rate holiday pay or sick leave accurately
- Avoid errors linked to UK bank holidays or regional differences
Less time spent double-checking spreadsheets means more confidence in every payslip.
For operational managers and rota planners
Staffing shifts without oversights is complex, especially in 24/7 environments. Use the calculator to:
- Schedule shifts around public holidays without manual guesswork
- Prevent accidental overstaffing or gaps due to miscounted days
- Synchronise rota planning with real-time absence data from Kelio’s platform
Accurate planning reduces last-minute changes, and the stress that comes with them.
For finance teams and project leads
Cashflow planning, contract billing and project delivery all rely on dependable schedules. With Kelio, you can:
- Forecast deadlines that respect both client expectations and working time limits
- Avoid late delivery penalties caused by misjudged lead times
- Align invoice dates and payroll cycles with business calendars
It’s a practical tool for anyone who needs predictability in project-driven environments.
For business owners and directors
Strategic planning requires reliable timeframes. Whether you’re evaluating staffing budgets or preparing a tender, Kelio offers:
- A clear overview of resource availability across all UK regions
- Support for compliance with holiday and working time regulations
- Integration with workforce analytics tools to guide high-level decisions
Explore Kelio’s workforce management tools
Kelio provides a powerful HR suite designed to simplify workforce management. From time and attendance tracking to absence planning, payroll integration and advanced rota scheduling, Kelio helps UK organisations stay compliant, accurate and efficient, every single working day.
Find out how Kelio’s workforce management solutions can help your business.
