It's about as long as The Revolutionary War (American).
(a.k.a. American War of Independence) (1775-83)
The War between Great Britain and the its thirteen colonies in North America (now the United States) for the independence of the United States is generally considered to have started with the Battle of Lexington and Concord on April 18th, 1775 (sometimes known as "The Shot Heard 'round the World") and to have concluded with the signing of the Treaty of Paris on September 3rd, 1783 — 0.8378 decades. A total of 25,000 Americans are estimated to have died as a result of the war.
It's about nine-tenths as long as King Tut's reign.
In other words, the length of King Tut's reign is 1 times 0.8378 decades.(a.k.a. Tutankhamun, a.k.a. Tutankhaten, a.k.a. tVwa:t-ʕa:nəx-ʔaˡma:n) (1333 BCE - 1324 BCE)
It's about one-and-three-tenths times as long as The Construction of the Chunnel.
In other words, 0.8378 decades is 1.311 times the length of The Construction of the Chunnel, and the length of The Construction of the Chunnel is 0.7628 times that amount.(a.k.a. Channel Tunnel, a.k.a. Le tunnel sous la Manche) (1987 thru 1994) (Folkstone, Kent, UK to Coquelles, Pas-de-Calais, France)
The construction crew of the Chunnel broke ground in England on December 15th, 1987 and the tunnel was inaugurated by the Queen of England and the President of France on May 6th, 1994 — a total construction time of 0.6382 decades. The 4.9 million cubic meters of chalk excavated from the UK side of the Chunnel was dumped within sea walls to create the 299,467.38 sq. km (74 acre) Samphire Hoe County Park near Dover, Kent.
It's about one-and-two-fifths times as long as World War II.
In other words, 0.8378 decades is 1.395 times the length of World War II, and the length of World War II is 0.7168 times that amount.(a.k.a. Second World War, a.k.a. WWII, a.k.a. WW2) (1939 - 1945)
It's about seven-tenths as long as FDR's Presidential Term.
In other words, 0.8378 decades is 0.6919 times the length of FDR's Presidential Term, and the length of FDR's Presidential Term is 1.445 times that amount.(a.k.a. Franklin Roosevelt, a.k.a. Franklin Delano Roosevelt) (1933-45)
It's about one-and-nine-tenths times as long as World War I.
In other words, 0.8378 decades is 1.92 times the length of World War I, and the length of World War I is 0.521 times that amount.(a.k.a. First World War, a.k.a. Great War, a.k.a. World War, a.k.a. War to End All Wars, a.k.a. WWI, a.k.a. WW1) (1914 - 1918)
It's about twice as long as The First walk around the world.
In other words, 0.8378 decades is 1.951 times the length of The First walk around the world, and the length of The First walk around the world is 0.5126 times that amount.(1970 - 1974) (Dave, John, and Peter Kunst) (including time in recovery)