How to Count Working Days and Plan Around Public Holidays

What counts as a working day?

A working day is a day on which normal business is carried out. In most of the world that means Monday to Friday. Saturdays, Sundays and public holidays are left out. The words working day, business day and workday are mostly used for the same thing, though some contracts and laws define them in their own way, so it is worth reading the definition if money or a deadline depends on it.

A calendar day is simply any day on the calendar, including weekends and holidays. When a document says 30 days, it usually means 30 calendar days unless it says working days or business days. That one word can turn a four-week period into a six-week one.

It also helps to know about half days and bank holidays. A shop may open on a public holiday, and a bank may close. A day can be a working day for a factory and not for a bank. The calculator on this site treats a day as a working day unless it is on your chosen weekend or is a national public holiday, because that is the most common definition and the one most people need.

How to count working days by hand

You do not need a tool for a short period. The method is simple, and understanding it makes you better at checking any calculator.

Start with the number of calendar days between your two dates. Count how many full weeks that contains, and multiply the weeks by five, since each full week holds five working days. Then add the working days in the leftover days at the start or end. Finally, subtract any public holidays that fall on a weekday inside the period.

• A period of exactly four weeks (28 days) has 4 × 5 = 20 working days before holidays.
• A period of 30 calendar days is four weeks plus 2 extra days. Those two days add anywhere from 0 to 2 working days, so the total is 20, 21 or 22.
• If there is one public holiday on a weekday in that period, take one more day off, so 19, 20 or 21.
• A normal year has 365 days, which is 52 weeks plus one day, so it holds 260 or 261 weekdays before holidays.

The part people forget is the leftover days. Whether those days land on a weekend or in the middle of the week is what changes the answer, and that depends on the weekday you start on. That is why you cannot simply say that 30 days equals 22 working days. It depends.

Are the start and end days included?

This single question causes more disagreements than any other. If you count from Monday 1 June to Friday 5 June, are there five working days or four?

If both days are included, there are five: Monday, Tuesday, Wednesday, Thursday and Friday. If the start day is left out, because the clock starts the next morning, there are four. If both ends are left out, there are three. None of these is wrong. They answer different questions.

Spreadsheet users will know the NETWORKDAYS function, which counts both the start and the end day, and the WORKDAY function, which adds a number of working days to a date. They are good models for how most people think. A deadline of ten working days from today usually means the tenth working day after today, so today is not counted. A count of days worked in a month, on the other hand, includes every day.

Our calculator has a checkbox for this, ticked by default. When your contract or a supplier's promise is involved, ask which way they count, write it down, and use the same rule.

The weekend is not the same everywhere

Most people reading this have a Saturday and Sunday weekend, but a good part of the world does not. Several countries in the Middle East, for example Saudi Arabia and Israel, have a Friday and Saturday weekend. Some places work a half day on Fridays or Saturdays. A few workplaces, such as hospitals, shops and restaurants, run seven days a week with staff on rotation.

This matters when you work across borders. A project with a team in London and a team in Riyadh has only four shared working days each week, Monday to Thursday, once you allow for the different weekends. A delivery promised in five working days by a supplier whose weekend is Friday and Saturday will not arrive when a Western buyer expects.

That is why our working days calculator lets you choose your weekend: Saturday and Sunday, Friday and Saturday, or Sunday only. Pick the one that matches the person doing the work. If you are unsure, ask them, and say which weekend you assumed when you write down a date.

Public holidays: why they make counting hard

Public holidays are the biggest source of surprise in a date calculation. They differ by country, and they move around in three ways.

Some holidays are on a fixed date, such as New Year's Day on 1 January. Some are on a rule, for example the first Monday of a month or the last Thursday of November. And some depend on the moon or on a religious calendar, such as Easter, Eid and Diwali, so their dates are different every year. Add to this that some countries move a holiday to the nearest Monday when it falls on a weekend, while others do not. In the United Kingdom, a substitute day is given when a bank holiday falls on a weekend. The United States federal government observes a Saturday holiday on the Friday before and a Sunday holiday on the Monday after.

Holidays can also vary inside one country. In the UK, England and Wales, Scotland and Northern Ireland have different bank holidays. In the US, each state sets its own list on top of the federal ones. In Germany and Switzerland, some holidays apply only in certain states or cantons.

All this is why holiday lists copied from last year's calendar go wrong. The sensible solution is to read them from a source that is kept up to date, which is exactly what our tools do.

How our tools keep holidays up to date

Both tools read their holiday dates live from Nager.Date, a free and open service that publishes public holidays for more than 200 countries and territories. When you pick a country and a year, your browser asks the service for that list and uses it straight away. Nothing is saved on our side, and nobody has to edit a table of dates by hand each year.

There are honest limits. Nager.Date lists national public holidays. Regional holidays that apply only to one state or province are left out, because they do not apply to everyone. India, the United Arab Emirates, Saudi Arabia and Pakistan are not covered by that service, so for those four our own server reads Google's public holiday calendars once a day, and we show only the days marked as public holidays. Optional festivals are left out. And a government can announce a change late, so dates for the distant future are a guide rather than a promise.

If a date matters, for a flight, a payroll run or a legal deadline, confirm it with the official government calendar. The tools are meant to make planning quick, not to replace the official source.

How to use the working days calculator in four steps

Here is the full process with our free working days calculator.

1. Choose the start date and the end date. The calculator opens with today and 30 days ahead, so you can see a result right away.
2. Pick a country so its national public holidays are removed, or choose No holidays to remove weekends only.
3. Choose your weekend, and tick or untick the box that counts the start and end days.
4. Read the working days at the top. Below you will see the calendar days, the weekend days, the holidays that were skipped, and the list of those holidays with their dates.

If you only want to see the holidays of a country, use the public holidays by country tool. It lists every national holiday for the year you pick, the weekday each one falls on, and the next holiday coming up.

Three worked examples

Numbers make this concrete. Here are three situations that come up all the time, with the arithmetic shown.

Example one: a delivery promise. A supplier confirms an order on a Monday and promises delivery in 10 working days. The clock starts the next morning, so day one is Tuesday. Counting ten working days forward, the last one is the Monday two weeks later, because each week has five working days and the first count began on Tuesday. If a public holiday falls on a weekday in between, the delivery moves one day later.

Example two: a notice period. A contract asks for 30 days' notice. If that means calendar days, you give notice on the 1st and you are free on the 31st, and weekends do not matter. If it means 30 working days, you are looking at around six weeks, because 30 divided by 5 is 6 full weeks, plus any holidays. That difference can mean an extra month of salary, or a missed start date at a new job, so ask which one it is.

Example three: the real cost of a day. Suppose a freelancer wants to earn 52,000 a year. A full-time year has 260 weekdays. Remove 10 public holidays that fall on weekdays and 25 days of leave, and 225 days are left to work. Divide 52,000 by 225 and the day rate comes to about 231. If the freelancer had divided by 260, they would have charged 200 a day and fallen short by about 7,000 over the year. Our day rate calculator helps with the full picture.

Deadlines, contracts and legal time limits

Whenever a date has legal or financial weight, be careful with the wording. Phrases such as within 14 days, no later than 5 business days and at least 30 clear days sound similar but mean different things.

Within 14 days normally means calendar days, including weekends. Five business days means working days. Clear days usually means that the day you give notice and the day the notice ends are both left out, so a notice of 7 clear days is 9 days from start to finish. Different countries and different contracts treat these terms differently, so never assume.

A few habits help. Write the actual date as well as the number of days, for example 14 days, until 22 March. Write the time zone if the other party is abroad. And if the deadline falls on a weekend or a holiday, check whether it moves to the next working day. Many rules say it does, but not all.

Working days, pay and invoices

Working days show up in money matters all the time. Banks process payments only on business days, so a transfer sent on Friday afternoon may not arrive until Monday or Tuesday, and longer if there is a public holiday. If your payment must land by a certain date, send it a few working days before.

Payment terms on invoices are another case. Net 30 normally means 30 calendar days from the invoice date. If you write 14 working days on an invoice, say so clearly, because many clients assume calendar days. Our invoice generator lets you set the due date, and our guide on how to make an invoice explains the other details to include.

For employees, the number of working days in a month changes pay for daily-paid and hourly workers. A month with 20 working days pays less than a month with 23. If you track the hours you work, our hours calculator adds them up, and the overtime pay calculator shows what extra hours are worth.

Planning time off: how to make long weekends

Public holidays are also an opportunity. The best use of annual leave is often to join days off to a holiday, and this is easy to plan once you can see the whole year.

If a holiday falls on a Thursday, taking Friday off gives you a four-day break for one day of leave. If it falls on a Tuesday, taking Monday does the same. These are called bridge days in some countries, and popular ones get booked early. A holiday in the middle of a week plus a few leave days can stretch to nine days off in a row for only four days of leave, if the weekends sit on either side.

A simple method is to open the list of holidays for your country, note which weekday each falls on, and look for the ones near a weekend. Then use the calculator with your leave dates to see exactly how many working days you are taking. You can also see how many holidays fall on weekends and are lost, which in some countries are not replaced by a day off.

Working with people in other countries

Remote work has made cross-border deadlines normal, and this is where the calendar causes the most trouble. A team in India, a client in the US and a freelancer in Germany do not share a weekend, and they share very few holidays.

Before you agree on a date, check three things. First, the weekend of the person who will do the work. Second, their national holidays in that period. Third, whether they have extra regional or religious days off that are not in a national list. A short message asking about this at the start of a project avoids a lot of awkwardness later.

Time zones add a final twist. A deadline of Friday evening in New York is already Saturday morning in Singapore. When a date is important, write the date, the time and the time zone together.

Common mistakes to avoid

Most date errors are small and easy to prevent. These are the ones we see most often.

• Treating 30 days as 30 working days, or the other way around.
• Forgetting to ask whether the first and last day are counted.
• Using last year's list of holidays. Dates move, and laws change.
• Assuming everyone has a Saturday and Sunday weekend.
• Ignoring regional holidays, which may apply to your team but not to the national list.
• Forgetting that a holiday on a weekend is sometimes moved to a weekday, and sometimes not.
• Promising a delivery date without leaving a buffer for the unexpected.

Avoid these and your estimates will be right far more often. A buffer of a day or two is cheap, and it is almost always worth building into any date you promise to someone else.

What a working days calculator can and cannot do

A calculator is very good at the arithmetic. It will never lose count, forget a leap day or mix up a weekday. It can also save hours when you have to check many dates.

What it cannot do is know your situation. It does not know your employer's own days off, a factory closure, a regional holiday, or a special rule in your contract. It relies on a holiday service for national dates, and it cannot cover countries that service leaves out. And it is not legal or financial advice.

Use it to plan and to cross-check. Then, when a date has real consequences, confirm it with an official source, your employer, or a qualified professional.

A quick checklist before you commit to a date

Keep this list near your desk. It takes a minute and prevents the most common date mistakes.

1. Decide whether the period is in calendar days or working days, and write it down.
2. Choose the country and the weekend of the person who does the work.
3. Decide if the start and end days are included, and use the same rule every time.
4. Remove public holidays, and check for regional or company days off.
5. Look at the result in the calculator and read the list of holidays it skipped.
6. Add a buffer of one or two days to any date you promise someone else.
7. Write down the final date, the time zone and the assumptions you made.

Do these seven things and your deadlines will be easier to meet, and much easier to defend if anyone asks how you got the date.

Questions people ask

Sources and further reading

• Nager.Date – Public holiday API
• GOV.UK – UK bank holidays
• US Office of Personnel Management – Federal holidays