Public holidays

File: data/public-holidays.json. Source: the law of 4 January 1974 on public holidays and its royal decree of 18 April 1974, art. 1; the Judicial Code, art. 50, 53 and 334.

Why it's useful

Every procedural deadline depends on the calendar. A deadline counts every day, Saturdays, Sundays and holidays included (art. 52 Ger.W. / C. jud.), but when its last day is a Saturday, a Sunday or a legal public holiday, that day moves to the next working day (art. 53). Three of the ten holidays move with Easter, so a hard-coded list goes wrong the next year. nextWorkingDay applies the art. 53 rule; getPublicHolidays gives the holidays of any year.

This is the building blocks, not a deadline calculator: when a deadline starts, how long it runs and whether it's extended depend on the procedure.

Source and updates

Source	Wet 4 januari 1974 and KB 18 april 1974, art. 1, on Justel
Built by	Hand: the ten rules, and the years a royal decree moved a holiday
Changes when	A law or decree changes the list, or moves a holiday for one year
Covers	1975 onwards, the first full year of the 1974 law: a day or year before it throws a RangeError
Checked	Against the Royal Observatory's list for 2024–2027 (test/calendar.test.ts); reviewed every year
Licence	CC BY 4.0

The file holds rules, not dates: a fixed day, or a number of days after Easter Sunday, which getEasterSunday computes for the Gregorian calendar.

Holiday	id	Day
New Year's Day	new-year	1 January
Easter Monday	easter-monday	Easter + 1 day
Labour Day	labour-day	1 May
Ascension Day	ascension	Easter + 39 days
Whit Monday	whit-monday	Easter + 50 days
National Day	national-day	21 July
Assumption	assumption	15 August
All Saints' Day	all-saints	1 November
Armistice Day	armistice	11 November
Christmas	christmas	25 December

When a holiday moves

In 2008 Ascension Day fell on 1 May, and the royal decree of 10 February 2008 moved it to 2 May for that year. replacements records such years; getPublicHolidays(2008) has Ascension Day on 2 May. A holiday that falls on a Sunday is not moved: employers give a substitute day off (art. 6 of the 1974 law), but the holiday itself stays where it is, and art. 53 already moves a deadline off a Sunday.

What isn't a legal holiday

• Community and regional holidays: 11 July (Flemish Community), 27 September (French Community), 15 November (German-speaking Community), 8 May and 20 September. They're days off for some public services, set by community or regional decree, not legal holidays: they don't move a deadline under art. 53, so they're not in this file.
• Days off for federal services: 2 November, 15 November and 26 December.
• Easter Sunday and Whit Sunday: Sundays already.

Judicial holidays

From 1 July to 31 August the courts sit in vacation chambers (art. 334). The judicial holidays don't stop deadlines running, with one exception: an appeal or opposition deadline that starts and ends during them is extended to the fifteenth day of the new judicial year, 15 September (art. 50, second paragraph). isJudicialHoliday tells you whether a day is in them; whether art. 50 applies depends on the deadline.

Other packages

General holiday packages list Belgium's holidays too. They answer "is this day a holiday?", but they mix in days that don't move a deadline and don't know the art. 50 and 53 rules:

Package	Language	Belgium
date-holidays	JS / TS	Country BE, names in Dutch, French, German and English, with the community holidays as regional holidays
Nager.Date	REST API	GET /api/v3/PublicHolidays/{year}/BE; free, no key
holidays	Python	Country BE with localized names
workalendar	Python	A Belgium calendar with working-day arithmetic (add_working_days)

Use one of them for days off in general, such as a school or office calendar; use this file when the day has legal consequences.

Use it

import { getPublicHolidays, isJudicialHoliday, nextWorkingDay } from 'belgica/calendar'

getPublicHolidays(2026).map((h) => h.day) // ['2026-01-01', '2026-04-06', …, '2026-12-25']
nextWorkingDay('2026-04-04') // '2026-04-07': Saturday, Sunday, then Easter Monday
nextWorkingDay('2026-04-03') // '2026-04-03': already a working day
isJudicialHoliday('2026-08-14') // true

Shape

interface PublicHolidays {
    description: string
    legalBasis: string
    fromYear: number // 1975
    holidays: PublicHolidayDefinition[] // the ten
    replacements: PublicHolidayReplacement[]
}

interface PublicHolidayDefinition {
    id: PublicHolidayId
    name: Translated // nl, fr, de
    rule:
        { type: 'fixed'; month: number; day: number } | { type: 'easter'; daysAfterEaster: number }
}

interface PublicHolidayReplacement {
    holiday: PublicHolidayId
    replaces: string // the day the rule gives, YYYY-MM-DD
    day: string // the day it's on instead
    legalBasis: string
}