Ever wondered how bank holiday dates are decided? Most of us just receive the calendar, but behind every public holiday lies a decision-making process — sometimes centuries old, sometimes surprisingly last-minute. From royal proclamations to moon-sighting committees, here is how the dates get set.
Fixed by law: the easy ones
Many holidays are simply written into legislation with a fixed rule. New Year’s Day is 1 January everywhere it is observed. In the UK, the Banking and Financial Dealings Act 1971 sets the framework for bank holidays, with the actual dates proclaimed each year. In the US, federal holidays follow rules like “the third Monday of January” for Martin Luther King Jr. Day or “the last Monday of May” for Memorial Day — the date moves, but the rule never changes, so calendars can be computed decades ahead.
Computed by formula: Easter and its relatives
Easter is the trickiest major holiday to pin down. Its date is determined by the computus — an ancient formula defining Easter Sunday as the first Sunday after the first full moon on or after 21 March. That single calculation cascades: Good Friday, Easter Monday, Ascension Day (39 days later) and Whit Monday all derive from it. In 2026, Easter Sunday falls on 5 April, which is why Good Friday is 3 April and Easter Monday 6 April across much of Europe. Nobody “decides” Easter each year; the formula does.
Declared by sighting: the lunar holidays
Islamic holidays — Eid al-Fitr, Eid al-Adha, the start of Ramadan, Ashura — depend on the physical sighting of the new crescent moon. Committees like Pakistan’s Ruet-e-Hilal Committee or Saudi Arabia’s moon-sighting authorities meet on the 29th day of the lunar month; if the crescent is seen, the new month begins, otherwise the current month completes thirty days. This is why Eid dates in our 2026 lists are marked “expected” — the announcement can shift them by a day, and it sometimes comes just 24–48 hours beforehand.
Proclaimed by governments: the political ones
Some holidays are created or moved by direct government action. The UK government can proclaim extra bank holidays — as it did for royal weddings and jubilees. Substitute days, like the UK’s Boxing Day substitute on 28 December 2026 (because Boxing Day falls on a Saturday), are announced through the same proclamations. New holidays altogether require legislation, which is why additions like Juneteenth (US, 2021) or new reconciliation days make headlines: they are genuinely rare political decisions, debated and voted on like any other law.
When calendars collide: 2026’s overlaps
Some years the different systems land on the same date, and 2026 has a beauty: in Pakistan, 23 March is both Pakistan Day and the expected third day of Eid-ul-Fitr — a national commemoration and a religious festival sharing a single day off. These collisions are handled pragmatically: the day remains one holiday, not two, and nobody gets an extra day in lieu. Weekend collisions are more common and better systematised — the UK’s substitute Boxing Day (28 December 2026) and the US observed Independence Day (3 July 2026) both exist precisely because the calendar collided with the weekend. Watching for collisions is the advanced level of holiday planning: they never create extra days off, but they explain why some years feel shorter on holidays than others.