Business Days Calculator

Business days are the days on which an organization is actually working, usually Monday through Friday except holidays. Contracts, invoices, court deadlines, delivery times and service level agreements almost always specify time periods in business days, while a wall calendar treats every day equally. This calculator compensates for this discrepancy both ways. It calculates the number of business days between two dates, and also shows dates that are a certain number of business days away from a given date.

Application:

Select the mode at the top. "Calculate number of business days between two dates" will tell you how many business days are in a given time period. Examples would be project durations, pay periods, notice periods, and tax filing deadlines. "Add or subtract business days" answers a different question: if ten business days pass from today, what is the end date?

Next, you'll set two rules that define what a business day is. In the Work Week setting, you specify which days of the week are working days, and in the Holidays setting, you select a calendar with holidays for countries to exclude. Any additional company holidays, regional saints' days or religious observances observed by employers not covered by these two settings must be entered into the Additional Holidays field.

Calculate number of business days between two dates:

The calculation tool examines the entire date range day by day and only keeps those days that are part of a work week and not holidays. Expressed as a formula:

Business days = calendar days – non-business days – holidays that fall on business days.

By default both the start and end date are calculated. This is usually "five business days from Monday to Friday" counting, also how spreadsheet programs do calculations. A concrete example: From Monday March 2nd (year 2026) until Friday March 20th (year 2026) there are 19 calendar days, of which four fall on a weekend and there are no holidays within the range. So business days is 15 days. This corresponds exactly to three full work weeks.

We are shifting the same 19 day period from Monday, January 12th (2026) to Friday, January 30th (2026). The number of calendar days and weekends remain the same but as Martin Luther King Day falls on a Monday, January 19th, this reduces the answer to 14 holidays that fall on a weekday taking up an entire day while holidays falling on a Saturday have no impact since they are not regular working days anyway.

The problem with the end date: where does the one-day discrepancy come from?

Even though the same two dates are used, two different tools can give you a day difference in results because of slightly different questions asked. The question "How many business days between these two dates?" includes the last date. The question "How many business days left until this date?" does not include it because that is one more day you have to work.

This is controlled by the "Calculate end date" option and is often the source of confusion when calculating business days. When this option is enabled, the calculation tool will match the behavior of NETWORKDAYS functions in spreadsheet programs and everyday understanding of a "five-day work week". When it is disabled, it produces the same result as normal date difference. If the end date itself is a business day, then the result is reduced by one day, while if the end date falls on a weekend, the result remains unchanged.

In fact, before discussing numbers you should first check the agreements. If the contract says "within 10 business days of receipt", then it must be clarified whether the day of receipt is considered as Day Zero or as Day One. These two interpretations lead to a difference of one whole day, and both are quite plausible in normal English.

Counting workdays: addition and subtraction

The second mode answers questions about a cut-off date. It counts days from the start date, skipping all non-business days until the specified number of days is reached. The start date itself is not counted. The first day is the next business day. This corresponds to the usual understanding of "ship within 2 business days".

If you count ten business days from a Monday without any holidays in between, it will be the Friday of the following week. So that's fourteen calendar days, not ten. If there is one holiday in that period, then the date moves to the next Monday. This is why the delivery time given in working days often sounds shorter than it actually is, and also explains why a delivery promised "5 business days" on Thursday before a long weekend may arrive nine calendar days later.

Negative numbers mean counting backwards and therefore answer questions that are really important to planners: If a deadline is fixed, when is the latest possible start date? If you enter the deadline as the start date and input negative working duration, then the calculation tool will show the actual latest start date.

Let's look at the two lines for June with 30 days again. The only difference is the holiday calendar. As July 4 (2026) falls on a Saturday, the national holiday is moved to Friday, July 3, which changes Tuesday to Wednesday in the answer.

Public holidays and compensatory days: rules

Holidays are not a fixed list but rather a set of rules that can change from year to year. Thanksgiving is the fourth Thursday in November, Memorial Day is the last Monday in May and Martin Luther King Jr. Day is the third Monday in January. The date for Easter Sunday, and therefore all associated holidays, is determined by a calculation based on the lunar calendar which means it can fall anywhere between March 22nd and April 25th. This calculator will generate all of the holidays based on those rules for any year within the range you specify whether that's five years or just two weeks from now so you'll get accurate results.

In the UK, Canada, and Australia, public holidays are moved to the nearest possible weekday so Christmas Day falls on a Monday if it is on a Sunday, for example, with Boxing Day falling on a Tuesday.

Regardless of the method, this has the same effect on working hours. However, it is easy to make mistakes when calculating manually. A holiday will be moved onto a weekday and take up that entire day, even if the date in the calendar falls on a weekend.

All eleven holidays in the year 2026 fall on a weekday. This is the worst situation for those who plan annual production capacity as each holiday represents one lost working day.

How many weekdays are there in the year 2026?

A year has 365 days. January 1 (corresponding to the year 2026, January) is a Thursday. Since this year is not a leap year, it contains 52 Saturdays, 52 Sundays and the rest are 261 working days. As all holidays in this year fall on working days, after subtracting the eleven US federal holidays, there will be 250 working days left, which corresponds to approximately 35.7 work weeks.

This difference is larger than the one implied by the rule of thumb "roughly 20 working days per month". While March, April, July and December have 22 working days each, February and November only have 19. The production capacity differs between the most productive and least productive months by 16%, which is enough to completely mess up a monthly delivery schedule based on average values.

Not everyone works Monday through Friday.

Many tools for calculating working days implicitly assume that Saturday and Sunday are weekends, some even explicitly state this which means they aren't suitable for all cases. This assumption is not true in many regions and industries around the world. In much of the Middle East Friday to Saturday is the weekend. Retail, hospitality, manufacturing and logistics often have six-day weeks. Support teams and data centers generally operate seven days a week. Additionally, four day workweeks are increasingly becoming reality rather than just an idea.

The working week configuration takes all cases into account and the following values are based on this setting. If you choose a six-day work week, then two weeks will contain twelve working days instead of ten. With a four-day work week it is eight days in those same two weeks. The number of working weeks is calculated by taking into account the actual working days so that each option remains meaningful.

There are situations where an accurate calculation is really important.

Payroll is a typical example. Banks only process transfers on business days, so if the payday falls on a holiday, then payment will be delayed, which is why most teams do payroll one or two business days early. This requires knowing exactly what days are affected. The same principle applies to prorated paychecks when only part of a month is being paid out. In this case, the denominator should not be a fixed number of days (21), but rather the actual number of business days in that month.

With legal and regulatory deadlines, mistakes are not allowed. Courts and agencies often require calculations to be made on business days, and once a deadline has passed there is no room for negotiation or relief. If a rule says that you must respond within "15 business days," then you should use the calendar of the jurisdiction in question, not your own calendar.

Logistics and service level agreements (SLAs) fall in between. If a shipping company says delivery is within "5 business days," that means nine calendar days if there's a long weekend in the mix. Similarly, a ticket filed on Friday afternoon versus one filed Tuesday morning has very different meanings when an SLA commitment is "2 business days."

In project planning the distinction between working days and calendar days is particularly important. Six weeks sounds like a lot of time but it equates to "30 working days" if you assume an eight hour day, which is 240 hours in total. If you subtract two bank holidays and one extra holiday then that's already 24 hours lost before the work has even started.

What this calculator doesn't take into account:

Regional and state holidays are intentionally excluded from the integrated calendar. The US list contains federal holidays, UK's list covers England and Wales bank holidays, Canada's list includes statutory holidays, and Australia's list has public holidays. These lists do not include country level holidays such as provincial or local bank holidays. If an employer also observes other holidays these can be entered in the "additional holidays" field.

Anzac Day is a good example of this. If 25 April falls on a weekend, some Australian states make up for it by having an extra day off the following Monday while others do not. So there's no one national solution. This calculator uses a conservative interpretation and does not take into account any compensatory days.

There is also no uniform definition of a half-day or early departure. Instead of defining your own rules, include the day in the calculation of working days and reduce the daily working hours. This way you can make changes where an adjustment really is needed while still keeping an accurate total number of working days.

This tool is for planning purposes. For legally binding deadlines you should check with the courts, authorities and business partners what rules apply. There are rules that count the first day, rules that move deadlines falling on a holiday to the next working day, and rules that use their own holiday calendar.