This explains the usual ways deadlines are counted. It isn't legal advice: a contract, court rule or law can set its own method, and that method is the one that counts.
Tick “Count weekdays only” in the date calculator to count Monday to Friday between two dates, or use the countdown to a date to see the working days left before a deadline.
Count business daysBusiness days and calendar days: the difference
Calendar days are every day: weekdays, weekends and public holidays. A 30-calendar-day period is 30 days on the calendar, whatever they are.
Business days (also called working days) are the days a business is normally open. In most countries that means Monday to Friday, minus public holidays. A period of 10 business days skips the weekends and any holidays in between, so it always takes longer than 10 calendar days.
If a deadline just says “days”, it usually means calendar days, but check the definitions section of the contract or rule. Many spell it out.
Converting business days to calendar days
With no holidays in the way, every 5 business days is one full week, so the quick rule is:
Calendar days ≈ business days ÷ 5 × 7
That gives 7 calendar days for 5 business days, 14 for 10 and 28 for 20. The exact answer depends on the day you start. Here are 10 business days counted from different days in mid-October 2026, with no public holidays in between and the starting day as day 0:
| Start (day 0) | 10 business days later | Calendar days |
|---|---|---|
| Monday, October 12 | Monday, October 26 | 14 |
| Wednesday, October 14 | Wednesday, October 28 | 14 |
| Friday, October 16 | Friday, October 30 | 14 |
| Saturday, October 17 | Friday, October 30 | 13 |
Each public holiday in the period pushes the end date one business day later, and if that lands on a weekend, to the following Monday.
Does the first day count?
Usually not. The common convention, used by most courts, government agencies and contracts, is that the day something happens (a notice is sent, an order is placed, a judgment is given) is day 0, and the count starts the next day. So a 5-day period starting on Monday ends on Saturday for calendar days, or the following Monday for business days.
The last day normally does count: the deadline is the end of that day, often at a set time such as 5 pm or 11:59 pm. Some rules instead count the first day, or say “within 10 days of” and mean the 10th day at the latest. When the wording is unclear, the safe choice is the earlier date.
This is the same inclusive-or-exclusive question that makes two people's day counts differ by one. The guide to counting days between dates goes through it in detail.
How US federal courts count time
The US Federal Rules of Civil Procedure are a good example of a precise rule. Under Rule 6(a)(1), for a period stated in days you:
- Leave out the day of the event that starts the period.
- Count every day, including Saturdays, Sundays and legal holidays.
- Include the last day, but if it falls on a Saturday, Sunday or legal holiday, the period runs on to the end of the next day that isn't one.
So court periods are calendar days with a weekend rule at the end. Since 2009, the federal rules no longer skip weekends for short periods; many state courts and other countries' courts have their own rules.
Public holidays and weekends are not the same everywhere
A business day in one place isn't one in another. The US has 11 federal holidays a year. In the UK, England and Wales have 8 bank holidays, Scotland 9 and Northern Ireland 10, and the dates differ. India, Canada and Australia add regional holidays by state or province.
Holidays move too. Some are fixed dates, some are weekday rules such as the fourth Thursday of November, and some follow the moon, like Easter, Diwali and Eid. When a fixed holiday falls on a weekend, many countries give the next weekday off instead. The guide to why holiday dates change explains how each kind is set.
The weekend isn't always Saturday and Sunday. Saudi Arabia's weekend is Friday and Saturday, and in Israel most businesses work Sunday to Thursday. The UAE moved its official weekend to Saturday and Sunday in 2022. Count with the working week of the place the deadline applies to.
Everyday deadlines and how they are usually counted
| Deadline | Usually counted in | What to watch |
|---|---|---|
| Shipping in 3 to 5 business days | Business days | The clock usually starts when the order is dispatched, not when you pay |
| Refund in 5 to 10 business days | Business days | Bank holidays add days; the bank may take longer to show it |
| Invoice due net 30 | Calendar days | Counted from the invoice date unless the terms say otherwise |
| 30-day return window | Calendar days | Often from delivery, not from the order date |
| Notice period of 2 weeks or 1 month | Calendar days or months | A month is a calendar month, not 30 days |
| Bank transfer settles next business day | Banking days | Weekends and bank holidays don't count |
For any of these, count the exact date once and write it down. The date calculator adds days to a date and counts the weekdays between two dates; public holidays aren't removed, so take off any that fall in your range.
Common mistakes
- Assuming “days” means business days. Unless the rule says business or working days, plan on calendar days.
- Counting the starting day. Most rules start counting the day after. Counting the first day makes your deadline a day early, which is safe, but counting both ends can make a business-day estimate a day short.
- Forgetting holidays that aren't yours. A supplier, bank or court in another country or state closes on its own holidays.
- Ignoring the time on the last day. A deadline on the 15th may mean 5 pm on the 15th in a particular time zone, not midnight where you are.
- Multiplying by 7/5 for long periods with holidays. The quick rule is only exact for whole weeks without holidays. For 60 business days, count the actual calendar.