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MasterMath

Deadline Calculator

An invoice on 30-day terms issued on 15 March falls due on 14 April in calendar days, and on the 27th if the contract says business days. Work out the exact deadline for a term of any kind.

Deadline date

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Deadline date—
Falls on a—
The term starts running on—
If you counted the other way—
From today that is—

How this was worked out

    How it is worked out

    deadline = start date + term, counting whichever kind of day applies

    Why it is done this way

    A term has three things people forget: when it starts running, which days it counts, and what happens if it lands on a holiday. Most often it starts the day after notice or issue, commercial terms run in calendar days and administrative ones in business days, and a deadline falling on a non-working day moves to the next working one.

    Step by step

    1. Find the day the term starts running: normally the day after the start date
    2. Count the days of the term, skipping weekends and holidays if they are business days
    3. If the term runs in months, step month by month and clip the day when the month is shorter
    4. Check whether the resulting day is a working day

    What is worth knowing

    Holidays are not filled in for you, and that is deliberate: no two public holiday calendars are alike, they change by country, region and town, and publishing one list here would mean vouching for it where it does not apply. Write them separated by commas in YYYY-MM-DD format and they will be skipped. The page flags a deadline that lands on a non-working day, but check the rule that governs your term, because not every procedure moves it the same way.

    Frequently asked questions

    When is an invoice on 30-day terms due?

    Thirty calendar days after the issue date, counting from the following day, unless the contract says otherwise.

    Are business days Monday to Friday?

    In most administrative procedures yes, minus public holidays. Some court calendars also exclude parts of the summer.

    What if it falls on a Saturday?

    Normally the deadline moves to the next working day, but that depends on the rule governing the term.