Labor Day is basically another name for May Day to which hence the name occurs every May 1rst. It celebrates the work force of the country and a good spring.
All workers and government jobs get the day off, so most businesses are closed on Labor Day. To celebrate many will just enjoy a nice day off from work and will plan fun activities with friends of family.
Labor Day came to be when there were work riots that broke out in different countries for bad work treatment. It called for a holiday to please the workers which was chosen to be May 1rst.