What counts as a business day
A business day is any Monday through Friday. Saturdays and Sundays are never business days under the standard definition used in US shipping, banking, and legal contexts, this is consistent across essentially every authoritative source on the topic. Some businesses also exclude public holidays from the count, but that part is optional and depends on the specific business or contract, not a universal rule.
Counting business days by hand
Count forward from the day after your start date, skipping every Saturday and Sunday, up to and including your end date. If holidays are also being excluded, skip those too. The tricky part isn't the concept, it's keeping track of exactly where the weekends fall as you count forward, especially across a month boundary.
What "3-5 business days" actually means
It's a range, not a promise of a specific day. The count starts the business day after the order or notice, skips weekends, and the actual delivery or response can land anywhere within that window. Here's the part that surprises people: the calendar-day length of "3-5 business days" changes depending on what day of the week you start.
Same "3-5 business days" promise, but a Friday order takes noticeably longer in real calendar time because a weekend sits inside the count.
Federal holidays and business days
The US recognizes 11 federal holidays a year. When one falls on a Saturday, it's typically observed the preceding Friday, and when one falls on a Sunday, it's observed the following Monday. Whether a specific business excludes these from its "business days" count varies, government offices, banks, and some shipping carriers usually do, while many retailers with weekend staff don't. Always check what a specific deadline or estimate actually means before assuming.
A worked example
Business days between Monday, March 2, 2026 and Friday, March 20, 2026, using this site's counting convention, the start date itself isn't counted, only the days after it up to and including the end date, weekends excluded, no holidays in this range:
This matches what the Business Days Calculator on this site returns for the same range. Some other calculators count the start date itself as well, which would give a different total for the identical dates, always check which convention a given tool or contract is actually using before trusting the number.
Frequently asked questions
How do you calculate business days?
Count forward from the day after your start date, skipping every Saturday and Sunday, up to and including your end date. If the business or context also excludes public holidays, skip those too. A business day is any Monday through Friday that isn't a holiday.
What does "3-5 business days" actually mean?
It's a range, not a promise of an exact day. Counting starts the business day after the order or notice, skips weekends (and often holidays), and the delivery or response can land anywhere in that 3-to-5-day window. A Friday order with a 3-5 business day estimate can land the following Wednesday through Friday, since the weekend in between doesn't count toward the total.
How long is 2 to 3 business days?
In calendar days, it depends entirely on where the range falls relative to a weekend. If it starts on a Monday, 2-3 business days lands Wednesday or Thursday of the same week, only 2-3 calendar days later. If it starts on a Thursday, the weekend pushes it out to the following Monday or Tuesday, 4-5 calendar days later even though the business-day count is identical.
Sources
- The Old Farmer's Almanac, Business Day Calculator
- FederalPay.org, Federal Holidays (citing 5 U.S.C. ยง 6103)