May Day — also called International Workers' Day or Labour Day — is marked on 1 May in over 80 countries. In 2027 it falls on a Saturday. The date commemorates a dramatic and tragic event in 1880s Chicago and the long fight for the eight-hour working day. Here's the history.
See the holiday page for Labour Day / May Day, or read about Labour Day dates by country.
Why is May Day on May 1?
The date comes from the United States, even though the US itself doesn't celebrate Labour Day in May. In the 1880s, American labour unions were campaigning for a standard eight-hour workday, and they chose 1 May 1886 as the deadline — calling a nationwide general strike.
The Haymarket affair, 1886
On 1 May 1886, hundreds of thousands of workers across the US went on strike. Three days later, on 4 May, a rally in Chicago's Haymarket Square turned violent when a bomb was thrown at police, who opened fire. Several people on both sides were killed.
The Haymarket affair became a defining moment for the international labour movement and a symbol of the struggle for workers' rights.
How May 1 became an international day
- 1889 — The Second International, a federation of socialist and labour parties meeting in Paris, declared 1 May an international day of demonstrations in memory of Haymarket and in support of the eight-hour day.
- 1890 — The first international May Day was held, with huge rallies across Europe and beyond.
- Over the following decades, 1 May became an official public holiday — and a day of marches and labour solidarity — across much of the world.
Why doesn't the United States celebrate it on May 1?
Ironically, the country where it began moved its holiday. Wary of the radical associations of May 1, the US government established Labor Day on the first Monday of September instead (officially from 1894). Canada followed the September model. So today:
- Most of the world: Labour Day / May Day = 1 May.
- United States & Canada: Labor Day = first Monday of September.
May Day's older meaning
Long before the labour movement, May Day was also a spring festival in Europe — celebrating the start of warmer days with maypole dancing, flowers and seasonal rites. In some countries the two meanings coexist on the same date.
Quick answers
Why is May Day on May 1? It commemorates the 1 May 1886 US general strike for the eight-hour workday and the Haymarket affair that followed in Chicago.
Is May Day the same as Labour Day? In most countries, yes — 1 May is International Workers' Day / Labour Day. But the US and Canada hold their Labor Day on the first Monday of September instead.
When is May Day 2027? Saturday, 1 May 2027 — it is always 1 May.
What is the Haymarket affair? A violent confrontation at a labour rally in Chicago on 4 May 1886 that became a symbol of the workers' rights movement and the reason 1 May was chosen as International Workers' Day.