It's about four-fifths as long as The Korean War
In other words, 30 months is 0.8090 times the length of The Korean War, and the length of The Korean War is 1.2360 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 — 37.08 months — 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, 30 months is 0.6260 times the length of The Civil War (American), and the length of The Civil War (American) is 1.60 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 — 47.90 months. 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, 30 months is 0.58190 times the length of The First walk around the world, and the length of The First walk around the world is 1.7190 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 four-month pause following an assault he suffered during the journey) on October 5th, 1974 — 51.550 months.
It's about three-fifths as long as World War I
In other words, 30 months is 0.5710 times the length of World War I, and the length of World War I is 1.750 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 52.50 months. 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 — 57.40 months after the armistice was signed.
It's about two-fifths as long as World War II
In other words, 30 months is 0.4160 times the length of World War II, and the length of World War II is 2.4040 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 72.10 months. 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, 30 months is 0.39110 times the length of The Construction of the Chunnel, and the length of The Construction of the Chunnel is 2.5570 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 76.630 months. 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, the length of King Tut's reign is 3 times 30 months.(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 — 100 months 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.