It's about four-fifths as long as The Korean War
In other words, 909 days is 0.8058 times the length of The Korean War, and the length of The Korean War is 1.241 times that amount.(1951-53) (to armistice signing)
The Korean War between North Korea (a.k.a. Democratic People's Republic of Korea, a.k.a. DPRK) and South Korea (a.k.a. Republic of Korea, a.k.a. ROK) began on June 25th, 1950 during the Cold War. The war paused with the signing of an armistice on July 27th, 1953 — 3 years, 1 month, and 2 days later — although the war is officially ongoing and marked by occasional border conflicts.
It's about three-fifths as long as The Civil War (American)
In other words, 909 days is 0.623 times the length of The Civil War (American), and the length of The Civil War (American) is 1.61 times that amount.(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 years, 11 months, and 4 weeks later. 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 The First walk around the world
In other words, 909 days is 0.5796 times the length of The First walk around the world, and the length of The First walk around the world is 1.725 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 121.70 days pause following an assault he suffered during the journey) on October 5th, 1974 — 4 years, 3 months, 2 weeks, and 1 day later.
It's about three-fifths as long as World War I
In other words, 909 days is 0.569 times the length of World War I, and the length of World War I is 1.76 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 years, 4 months, and 2 weeks. 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 years, 9 months, 1 week, and 5 days after the armistice was signed.
It's about two-fifths as long as World War II
In other words, 909 days is 0.4144 times the length of World War II, and the length of World War II is 2.413 times that amount.(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 years and 1 day. Also the deadliest conflict in history, the war had an estimated 60 million casualties globally.
It's about two-fifths as long as The Construction of the Chunnel
In other words, 909 days is 0.3896 times the length of The Construction of the Chunnel, and the length of The Construction of the Chunnel is 2.567 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 years, 4 months, 2 weeks, and 6 days. 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 three-tenths as long as King Tut's reign
In other words, 909 days is 0.3 times the length of King Tut's reign, and the length of King Tut's reign is 3 times that amount.(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 — 3,000 days 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.