In accordance with the Uniform Monday Holiday Act passed by the U.S. Congress in 1968, observation of Memorial Day occurs on the last Monday in May for the first time, rather than on the traditional Memorial Day of May 30.
The Uniform Monday Holiday Act (Pub.L. 90–363, 82 Stat. 250, enacted June 28, 1968) is an Act of Congress that moved permanently to a Monday three Federal holidays in the United States—Washington's Birthday, Memorial Day, and Labor Day—and that made Columbus Day a federal holiday, also permanently on a Monday. This created long weekends with three days off ending with the holidays, such as Memorial Day Weekend and Labor Day Weekend.
Veterans Day was moved from November 11 to the fourth Monday in October but in 1978 it was returned to November 11, the actual date of the end of World War I (see Armistice of 11 November 1918) and celebrated in several European countries as Armistice Day.
The Act was signed into law on June 1, 1968, and took effect on January 1, 1971.