International Workers' Day (also known as May Day) is a celebration of the international labour movement and left-wing movements. It commonly sees organized street demonstrations and marches by working people and their labour unions throughout most of the world. May 1 is a national holiday in more than 80 countries. It is also celebrated unofficially in many other countries. May Day is related to the Celtic festival of Beltane and the Germanic festival of Walpurgis Night. May Day falls exactly half a year from November 1, another cross-quarter day which is also associated with various northern European pagan and the year in the Northern hemisphere, and it has traditionally been an occasion for popular and often raucous celebrations. As Europe became Christianized the pagan holidays lost their religious character and either changed into popular secular celebrations, as with May Day, or were merged with or replaced by new Christian holidays as with Christmas, Easter, Pentecost and All Saint's Day. In the twentieth century, many neopagans began reconstructing the old traditions and celebrating May Day as a pagan religious festival again.