Well, the truth is:
International Worker's Day
International Workers' Day (a name used interchangeably with May Day) is the commemoration of the Haymarket Riot of 1886 in Chicago, and a celebration of the social and economic achievements of the international labor movement. The 1 May date is used because in 1884 the Federation of Organized Trades and Labor Unions, inspired by labor's 1872 success in Canada, demanded an eight-hour workday in the United States to come in effect as of May 1, 1886. This resulted in a general strike and the riot in Chicago of 1886, but eventually also in the official sanction of the eight-hour workday. The May Day Riots of 1894 and May Day Riots of 1919 occurred subsequently. In 1889, the first congress of the Second International called for international demonstrations on the 1890 anniversary of the Chicago riot. These were so successful that May Day was formally recognized as an annual event at the International's second congress in 1891.
I had a distant relative that died in the Riots when he made the mistake of seeing what all the fuss was about. A stray bullet killed him. He was an immigrant.
It is interesting to look at the history of certain holidays and see where they began. It seems that most holidays begin with birth or death.