Mathematics · dates

Countdown & Working Days

How long until any date — in every unit at once, and in the one that usually matters: working days.
days · weeks · working days

Counting to

Whose holidays

    From now

    snapshot
    days

    Every day between

    working day weekend bank holiday
    The awkward bit

    “Three months” is not a length of time

    Days, weeks, hours and minutes are all fixed multiples of each other, so converting between them is arithmetic. Months and years are not. A month is whatever the calendar says it is — 28, 29, 30 or 31 days — so “three months from now” lands on a different number of days depending entirely on which three months you happen to be crossing.

    The same three months, four lengths

    From 31 January it is 89 days. From 30 November, 90. From 31 May, 92. That is a spread of three days on an interval most people would call the same length — and it is why this page gives you the calendar answer (years, months and days) and the arithmetic answer (total days) side by side rather than pretending they are the same question.

    There is a second trap underneath it. Adding a month to 31 January has no correct answer, because 31 February does not exist. Every date library in the world clamps it to 28 February, which means adding a month and then subtracting one does not always bring you home. This page clamps the same way, because everything else does — but it is a convention, not a fact.

    The useful number

    Working days, and why nobody guesses them well

    “Six weeks” sounds like plenty. Six weeks across Christmas is about twenty-two working days, and four of those are the ones nobody answers email on. The gap between calendar time and working time is where schedules quietly go wrong, and it is worst exactly when you can least afford it.

    A calendar year is not 260 working days

    It is 260, 261 or 262 weekdays depending on which day the year starts on and whether it is a leap year — and then the bank holidays come off. England and Wales get eight, which lands a normal year at about 253 working days. Scotland gets nine but loses Easter Monday; the United States gets eleven federal holidays, several of which are not days off for most private employers at all.

    How are the bank holidays worked out?

    Computed, not listed. The fixed ones are trivial; the moving ones are not. Good Friday and Easter Monday hang off Easter, which is found with the anonymous Gregorian computus — the same algorithm that has set the date since 1582, based on the ecclesiastical full moon rather than the real one. The May and August holidays are the first or last Monday of their month. That means this page is right for any year you type, not just the ones somebody remembered to hard-code.

    What happens when Christmas is a Saturday?

    It gets substituted to the next weekday, and so does Boxing Day — but they are not allowed to land on each other, so a Saturday Christmas pushes Boxing Day to the Monday and Christmas to the Tuesday. Getting this wrong is the single most common bug in home-made working-day calculators, and it only shows up once every few years.

    Why is the live count not running by default?

    Because a page that starts moving on its own is a page you cannot read. Press Count live and it ticks to the second; leave it and you get a snapshot taken when the page loaded. If you have reduced motion turned on, the live count stops on its own.

    What this page assumes

    That a working day is a weekday that is not a public holiday. That is a definition, not a measurement: it knows nothing about your leave, your industry's shutdowns, part-time patterns, or the fact that the days between Christmas and New Year are technically working days that almost nobody works.

    That everything happens in your device's time zone, and that the calendar is proleptic Gregorian. Crossing a daylight-saving boundary makes one day 23 or 25 hours long, so an hours-and-minutes countdown across the change is out by an hour against the naive arithmetic — this page counts real elapsed time, so it stays right and the days figure is the one that looks odd.

    Holiday sets cover England & Wales, Scotland and US federal. Northern Ireland, the Republic of Ireland, and every regional and local holiday are absent. Verified in countdown_model.py.

    Field notes

    Dates behave worse than you think

    Version history · unchanged

    No change to this page at all since the earliest archived release (v5.66). The full history for the site is in the changelog.

    The arithmetic is exact; the holiday lists are a definition. Bank holidays are computed from the standard rules and substitution conventions, which have changed before and can be added to by royal proclamation — a one-off holiday for a coronation or a jubilee will not be here. Check an official calendar before you promise anyone a date. See Sources.