April 30, Valborgsmässoafton. As mentioned earlier, bonfires are lit, and when the crackling of the fire is at its height, a number of people step forward, many wearing peaked caps with a white top. They proceed to sing a number of songs, which are the same everywhere in the country and maintain that this evening marks the end of winter and the coming of spring.
The singing becomes more organized on May First, “Första Maj,” when student and men’s choirs gather on university steps and in parks all over the country. Listen to Valborgskören, Umeå University: Sköna Maj Välkommen...

May First, other than Sweden’s National Day on June 6, is the only non-religious holiday in Sweden.
It was no coincidence when, during the 1880s, the Labor movement chose May Day for its annual manifestation. In many parts of Europe the day had been a secular festival, a kind of administrative New Year’s Day in bygone society. This was the day when accounts for the year were presented and new officers were elected for the year to come. Work would be at a standstill, giving journeymen and apprentices a day off without any need for churchgoing. In Stockholm from the early 19th century onward, May Day developed into a popular festival in Djurgården Park, complete with procession and royal visit.

It all started in the U.S.
Although America’s Labor Day is celebrated the first Monday in September, the international celebration of labor, known as May Day on May 1, has more to do with events in the U.S. than most people know. The Chicago Haymarket affair is generally considered significant as the origin of international Labor Day, the May Day observance for workers.
Following the Civil War and the 1873-79 depression, America had seen a rapid expansion of industrial production. The waves of immigrants at the time allowed for a steadily growing workforce. But conditions were often horrendous, Americans worked an average of slightly more than 60 hours during a six-day workweek and child labor was common.
In October 1884, a convention held by the Federation of Organized Trades and Labor Unions unanimously set May 1, 1886, as the date by which the eight-hour workday would become standard. As the chosen date approached, U.S. labor unions prepared for a general strike in support of the eight-hour day, and on Saturday, May 1, 1886 hundreds of thousands of workers went on strike and rallies were held throughout the United States, with the cry, “Eight-hour day with no cut in pay.”
The Haymarket affair (a.k.a. Haymarket massacre or Haymarket riot) was the aftermath of a bombing that took place at a labor demonstration a few days later on May 4 at Haymarket Square in Chicago. It began as a peaceful rally in support of workers striking for an eight-hour day and in reaction to the killing of several workers by police the previous day. An unknown person threw a dynamite bomb at police as they acted to disperse the public meeting. The bomb blast and ensuing gunfire resulted in the deaths of seven police officers and at least four civilians; scores of others were wounded.
International Workers’ Day, a celebration of laborers and the working classes that is promoted by the international labor movement and socialists, is celebrated on that day to commemorate the Haymarket affair. Sweden held its first May 1 Workers’ Day in 1890, organized by the social democrats. Today’s May 1 demonstrations still engage thousands of people in many cities in Sweden although the messages you find on the placards aren’t always related to working conditions.
Labor Day in the U.S., this year on September 5, became an annual federal holiday in 1894.