Country calendars: three origins of a closed day

A national holiday calendar is a legal instrument before it is a list. Most of what goes wrong with one comes from treating it as a list: copying the dates, losing the rules that produced them, and finding out a year later that the copy and the law had parted company.

This page is about the instrument behind country calendars: where a country's closed days come from, how they are published, why two countries' calendars are not comparable objects, and how to take one from its publisher in a form that will still be right when you need it.

What to take away

A closed day has one of three originsfixed by statute, derived by a formula in statute, or declared by the executive for one year. Each origin has a different lead time and a different failure mode.
The publishing chain runs from law to annual instrument to official page to copies. Trust falls at every step, and this site is a copy, which is why it prints no dates for any country.
Take a calendar as a document with fields, not as a row of dates, and record the publisher and the date you took it.

Three kinds of closed day

Fixed by statute. The law names a calendar date. It falls on a different weekday each year and on a weekend in some years, which is where substitute rules enter. Lead time is effectively unlimited; the risk is that the statute is amended and your copy is not.

Three kinds of closed day

Fixed by statute

What the law names: A calendar date
How date is found: Read the date
Lead time: Unlimited
Main risk: Statute amended

Fixed by formula

What the law names: A rule
How date is found: Apply the rule
Lead time: Unlimited
Main risk: Stale stored result

Declared

What the law names: Nothing in advance
How date is found: Read the declaration
Lead time: Days to months
Main risk: Not yet declared

Fixed by formula. The law names a rule: a given weekday of a given month, or a day relative to another observance. The date moves every year and can only be found by applying the rule. A copy that stores last year's result is wrong this year by construction.

Declared. The executive announces a day for one year, by proclamation, order or gazette notice. Some are routine and announced well ahead; some mark an event and are announced with days of notice. No copy can contain a day that has not been declared yet, so every future-year list is incomplete until the declaring authority has finished declaring.

A fourth source sits across all three: observances tied to a lunar or religious calendar, whose civil date may be confirmed by a religious authority close to the day. Countries that observe them publish provisional dates and confirm later, and a list that does not mark which dates are provisional is hiding that.

The publishing chain

Layer	Who produces it	What it fixes	What it cannot tell you
Primary law	The legislature	The fixed dates, the formulas, and who may declare more	Which days were declared this year
Annual instrument	The executive, by proclamation, order or gazette	This year's declared days and any substitutions	Next year's, or a day declared after it was issued
Official page	A ministry or agency	A readable list combining the layers above	Whether it has been updated since you read it
Copies	Calendar apps, vendors, general websites	Nothing; a copy has no authority	Which layer it was copied from, and when

The UK is a clean illustration of the shape without any need for dates. The Banking and Financial Dealings Act 1971 sets out certain bank holidays in a schedule and provides for others to be appointed by royal proclamation. So some days are fixed in the statute and some are declared year by year.

From law to your copy

Primary law fixes dates and formulas
Annual instrument declares this year's days
Official page combines the layers
Copies have no authority

The government then publishes the resulting list for each part of the UK on the UK bank holidays page, which is the layer you take a list from. The page's dates are not reproduced here, and should not be reproduced anywhere that cannot update when the page does.

Why two countries' calendars are different objects

Not merely different dates. The documents differ in kind.

The working week.Which days are rest days is a national or regional convention, and a calendar's closed days only mean anything against its own week.
Scope.One country's list binds public offices only. Another's binds banks and courts too. A third has separate lists for each. "Public holiday" does not name a consistent legal category across borders.
Regional annexes.Federations and countries with devolved regions publish a national core plus regional additions, and the additions are sometimes in separate instruments from separate bodies.
Substitution.When a fixed date falls on a rest day, some calendars move it to the next working day, some to the previous, some observe both weekend days on the following two working days, and some do not move it at all. This rule is part of the calendar and it differs between countries that share the same nominal dates.
Half days and bridging days.Some calendars include afternoons off before an observance, or a day that joins an observance to a weekend, and whether those count as closed for deadline purposes is often decided by a different body from the one that granted them.

The consequence is that a "country calendar" in a tool is at best one country's list for one scope under one substitution rule, as of one date. The tool rarely says which.

Reading a published list

Capture these fields, and refuse a list that will not let you fill them in:

Field to capture / What it settles

Publisher and instrument: The body and the document, so the list can be re-checked at source
Scope: Public offices, banks, courts, all employers, or a subset
Region: The whole country, or a named part
Year: Lists are per year; a list with no year is a template
Each day's origin: Fixed, formula or declared, so you know which ones can still change
Substitution rule: Stated in the publisher's words, not inferred from the dates
Provisional markers: Which dates await confirmation
As-of date: The date you took the list, written by you

The last row is the one everyone skips. A list without an as-of date cannot be told apart from an older or newer version of itself.

Taking a list into your own calendar

Identify the body whose closed days actually govern what you are counting: the court, the agency, the payment system, the employer. Its list may differ from the national one, and where it does, its list wins.
Go to that body's own publication, or to the official page it says it follows.
Record the fields above and store a copy of the document, not a link to a page that will change.
Note when the next annual instrument is usually issued, and check again then.
Before any deadline that crosses a declared or provisional day, check once more.

The arithmetic matches any other closure. A closed day that would have been a working day removes one working day from the count. A closed day on a rest day removes nothing unless it is substituted.

The forward count is under adding business days, the backward one under subtracting business days. counting between two dates covers which endpoints are in.

Common questions

Why will this page not just list the days?

Because it would be a copy, four layers down from the law, with no ability to update when a day is declared or a rule amended. A wrong list is worse than none: it produces a confident answer.

How far ahead is a national calendar reliable?

Fixed and formula days are reliable as far ahead as the statute stands. Declared days are reliable from the moment of declaration and not before. A list for a year that has not started is a forecast for everything in the third category.

Do neighboring countries with the same observances have the same calendars?

Rarely. Substitution rules, scope and regional annexes differ, so the same named observance can close different offices on different days on each side of a border. Counting across a border, whether by working days in a month or working hours, needs a calendar per side.

Which is more likely to be wrong, a tool's built-in calendar or my own copy?

Whichever has no as-of date. A tool that cannot say which publisher and which date its list came from is a copy of unknown vintage, and so is a spreadsheet tab someone typed two years ago.