In one line
Working days, Monday to Friday, used in contracts and terms where weekends do not count.
What it means in practice
A business day is any day from Monday to Friday. Whether public holidays count depends on the contract and on where you are, and because holidays differ by country and by state they are usually named explicitly rather than assumed.
The distinction matters most in payment terms and lead times. Ten business days is fourteen calendar days; thirty business days is about forty-two. On a thirty-day term the two conventions are nearly two weeks apart.
Net terms normally mean calendar days unless the contract says otherwise. If it says working days, it means something materially different and it is worth reading twice.
Example. Ten business days from a Friday lands on the Friday a fortnight later: four weekend days are skipped, so fourteen calendar days pass.
The mistake to avoid
Assuming net 30 means thirty business days. It almost never does, and the person on the other side is usually counting calendar days.
Work it out
Why holidays are left to you
There is no single answer to whether a public holiday is a business day. It depends on the country, often on the state or province, sometimes on the industry, and frequently on what the contract says. A calculator that quietly applied one country's calendar would give most of its users a confident wrong answer, so this one counts weekends only and leaves holidays visible.
A second example
A supplier quotes fifteen working days for a fabricated part, ordered on a Monday. That is three full weeks, landing on the Monday of the fourth week, not the Tuesday of the third. Booking the install for day sixteen calendar is how a crew arrives to no part.
Related terms
- Billable hoursThe hours a client actually pays for, after time off and all the work nobody charges for.
- Days past dueHow many days have passed since an invoice's due date, not since it was raised.