"Mayday has traditions dating back centuries to pagan rituals. In much of 20th century Europe, the holiday became a "Labor Day" in honor of workers, and promoted by Labor Unions. Celebrations of May Day were akin to our celebrations of Christmas, while the origins of the holiday are purported to be the Nativity [this is actually incorrect]; the celebration is mixed with paganistic emblems and practices which also have lost contemporary meaning.
"The Nazis wished however to replace both the liturgical Christian and Secular Calendar events with their own commemorative days, based on 'solar' calendars associated with pagan worship. This meant the re-introduction of such days as Beltane, or Mayday which indicated fertility rites and 'renewal' and went handily along Nazi promotion of the promotion of large German-Aryan families even giving out interest-free loans to new married couples which would become grants which did not have to be repaid upon the birth of enough children."
Also, information about the maypole and its importance to the Nazis.