How due dates are counted

How a due date is worked out

Add the days in the terms to the invoice date. Net 30 on an invoice dated 1 August is due on 31 August — the count starts the day after the invoice date and the invoice date itself is day zero. Net terms mean calendar days unless your agreement says otherwise, so weekends and public holidays are inside the count, not skipped.

The count, step by step:

1. Start from the invoice date. It is day zero; the count begins the day after.
2. On end-of-month terms, move the start to the last day of the month the invoice is dated in.
3. Add the days in the term — calendar days, unless your agreement says working days.
4. If the result lands on a weekend, it stays there unless your agreement moves it; see below.

End of month is a different starting line, not a longer term

"Net 30 from end of month" — written EOM, and common in Europe and across much of Asia — counts from the last day of the month the invoice is dated in. An invoice dated 2 January on those terms is not due on 1 February. It is due on 2 March: the count starts on 31 January. The same term on an invoice dated 30 January is due on 2 March as well.

That is the point of it. A month's invoices fall due together, which is easier for a client paying in runs, and it can hand an invoice issued early in the month nearly twice the time its name suggests. Worth knowing which one you agreed to before you chase it.

Calendar days or working days

Standard Net terms are calendar days. Counting in working days means Monday to Friday only, which is what phrases like "within 10 business days" describe, and it always lands the due date on a weekday. For a working-day count on its own, away from payment terms, counting working days explains why two sensible counts differ by one, and the business days calculator runs it.

There is no public holiday table on the calculator, on purpose. Holidays depend on the country, often on the region inside it, and on the year. A calculator that skipped the wrong country's holidays would be wrong in a way that looks authoritative, which is worse than not skipping any. If your terms exclude holidays, count them yourself from the date the calculator gives you.

A due date that lands on a weekend

In calendar mode it stays there, because that is what the term says, and the calculator names the next working day beside it. Some agreements move a weekend or holiday due date to the next working day; plenty do not, and a payment that arrives on the Monday is late by the letter of terms that say nothing. If it matters, put it in writing before the first invoice rather than after the first late one.