It's about as long as World War II.
In other words, the length of World War II is 1.001 times 6 years.(a.k.a. Second World War, a.k.a. WWII, a.k.a. WW2) (1939 - 1945)
The most widespread war in history, the Second World War is generally considered to have started with the German invasion of Poland on September 1st, 1939 and to have until the surrender of Japan on September 2nd, 1945, a total of 6.004 years. Also the deadliest conflict in history, the war had an estimated 60 million casualties globally.
It's about nine-tenths as long as The Construction of the Chunnel.
In other words, 6 years is 0.9392 times the length of The Construction of the Chunnel, and the length of The Construction of the Chunnel is 1.065 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 6.382 years. 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 I.
In other words, 6 years is 1.37 times the length of World War I, and the length of World War I is 0.73 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)
World War I is considered to have begun with the assassination of Austrian Archduke Franz Ferdinand on June 28th, 1914 and to have lasted until the signing of the armistice with Germany on November 11th, 1918, for a total of 4.37 years. However, the Treaty of Versailles which ended conflicts between the major powers was not signed until June 28th, 1919 and the last formal peace treaties were not signed until August 23rd, 1923 — 4.78 years after the armistice was signed.
It's about seven-tenths as long as The Revolutionary War (American).
In other words, 6 years is 0.7161 times the length of The Revolutionary War (American), and the length of The Revolutionary War (American) is 1.396 times that amount.(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 — 8.378 years. A total of 25,000 Americans are estimated to have died as a result of the war.
It's about one-and-two-fifths times as long as The First walk around the world.
In other words, 6 years is 1.397 times the length of The First walk around the world, and the length of The First walk around the world is 0.7158 times that amount.(1970 - 1974) (Dave, John, and Peter Kunst) (including time in recovery)
On June 20th, 1970, Dave Kunst set out from Waseca, Minnesota with $1,000 and a mule. Kunst completed his walk around the world (with a 0.3331 years pause following an assault he suffered during the journey) on October 5th, 1974 — 4.293 years.
It's about one-and-a-half times as long as The Civil War (American).
In other words, the length of The Civil War (American) is 0.667 times 6 years.(a.k.a. War Between the States, a.k.a. the Great Rebellion, a.k.a. the War of the Rebellion) (1861-65) (United States)
The deadliest war in American history, the American Civil War is generally considered to have begun on with the attack on Fort Sumter on April 12th, 1861 and to have lasted until the surrender of Robert E. Lee's army on April 9th, 1865 — 3.99 years. A total of 620,000 American (including Confederate) soldiers are estimated to have lost their lives due to the war.
It's about three-fifths as long as King Tut's reign.
In other words, the length of King Tut's reign is 2 times 6 years.(a.k.a. Tutankhamun, a.k.a. Tutankhaten, a.k.a. tVwa:t-ʕa:nəx-ʔaˡma:n) (1333 BCE - 1324 BCE)
Pharaoh of the 18th dynasty, Tutankhamun begin his reign at the age of eight in 1333 BCE and remained pharaoh until 1324 BCE — 9 years later. When artifacts from Tut's tomb were on display at the Metropolitan Museum of Art (New York City, New York) from late 1976 to 1979, they were viewed by an estimated 8 million people.