What is labour day? i hear it being mentioned in american tv programmes but iv neva known wat it means?!?

Labor Day (this is the American spelling) is a public holiday celebrated the first Monday in September in the United States (and in Canada where it is Labour Day). It honors working people but is, deliberately, distinct from the socialist May Day (May 1st) holiday observed elsewhere. It traditionally marks the end of summer and the return to school the next day.