ORIGIN
The earliest May Day celebrations appeared in pre-Christian Europe, as in the Celtic celebration of Beltane, and the Walpurgis Night of the Germanic countries. Many pre-Christian indigenous celebrations were eventually banned or Christianized during the process of Christianization in Europe. As a result, a more secular version of the holiday continued to be observed in the schools and churches of Europe well into the 20th century. In this form, May Day may be best known for its tradition of dancing the Maypole and crowning of the Queen of the May. Today various Neopagan groups celebrate reconstructed (to varying degrees) versions of these customs on 1 May.
The day was a traditional summer holiday in many pre-Christian European pagan cultures. While February 1 was the first day of Spring, May 1 was the first day of summer; hence, the summer solstice on June 25 (now June 21) was Midsummer. In the Roman Catholic tradition, May is observed as Mary's month, and in these circles May Day is usually a celebration of the Blessed Virgin Mary. In this connection, in works of art, school skits, and so forth, Mary's head will often be adorned with flowers. Fading in popularity since the late 20th century is the giving of "May baskets," small baskets of sweets and/or flowers, usually left anonymously on neighbors' doorsteps.Traditional May Day celebrations
May Day marks the end of the uncomfortable winter half of the year in the Northern hemisphere, and it has traditionally been an occasion for popular and often raucous celebrations, regardless of the locally prevalent political or religious establishment. As Europe became Christianized the pagan holidays lost their religious character, They either morphed into popular secular celebrations, as with May Day, or were replaced by new Christian holidays as with Christmas, Easter, and All Saint's Day. In the start of the twenty-first century, many neopagans began reconstructing the old traditions and celebrating May Day as a pagan religious festival again.visit The World Wide Web Addict for more infos about May Day which is also known as International Labour/Workers Day
source: wikipedia.org