World Worker’s Day Images,greeting Wishes : May Day or International Workers’ Day or Labor Day is the celebration of labor and the working classes that occurs on 1st May 2015. It is a national public holiday in more than 80 countries. It is also a traditional spring holiday in many cultures. It is a day to honor workers’ rights.Labour Day is the major event occurs in almost every country of the world. In most of the countries, Labour Day and International Workers’ Day is celebrated on the same day on 1st of May. So it is also called as May Day. But in other countries the celebration date differs according to the Labour movement in that country. If you will ask Labour Day celebration date on US & Canada then it falls on the 1st Monday of September month.