On May 5, 1868 General John Logan, national commander of the Great Army of the Republic, officially proclaimed Decoration Day. It was first observed on May 30, 1868 when the graves of soldiers at Arlington National Cemetery who had died during the US Civil War were decorated with flowers. That date was chosen because during the Civil War there were no known battles to have been fought on that particular day in the month of May. In 1967 Decoration Day was officially renamed as Memorial Day. In 1971 Memorial Day became a Monday holiday on the last Monday of May.
In 2010, Memorial Day is on 31st May.
Memorial Day has fallen on May 31st in several years since it was established as a federal holiday, particularly after the Uniform Monday Holiday Act was enacted in 1971. Notable years when Memorial Day occurred on May 31st include 1971, 1976, 1982, 1987, 1993, 1999, and 2004. The holiday is observed on the last Monday of May, so it will continue to fall on May 31st in future years when the calendar aligns accordingly.
The 25th of May, and the latest it can occur is the 31st. Because it is the last Monday in May, there are seven or fewer days remaining in the month if it were to fall on the 25th.
October 31st 1997 was a Friday.
Friday
31st of January 1978 fell on a Tuesday.
Memorial Day 2012 fell on Monday, May 28th.
It was a Monday.
It was a Saturday.
It was a Tuesday.
Memorial Day (before 1967 it was officially called Decoration Day) was observed on May 30th of every year. In 1971 it was changed to being on the last Monday of May. It was not changed to the 31st of May. Occasionally the last Monday of May is the 31st. That last happened in the year 2010 and will next occur in the year 2021.
Memorial Day always takes place on the last Monday of May.