How long is 654 days?
It's about three-fifths as long as The Korean War
The length of The Korean War is about 1,128 days.
(1951-53) (to armistice signing)
It's about two-fifths as long as The US Civil War

The length of The US Civil War is about 1,460 days.
(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)
It's about two-fifths as long as The First walk around the world
The length of The First walk around the world is about 1,568 days.
(1970 - 1974) (Dave, John, and Peter Kunst) (including time in recovery)
It's about two-fifths as long as World War I
The length of World War I is about 1,600 days.
(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 three-tenths as long as World War II
The length of World War II is about 2,193 days.
(a.k.a. Second World War, a.k.a. WWII, a.k.a. WW2) (1939 - 1945)
It's about three-tenths as long as The Construction of the Chunnel
The length of The Construction of the Chunnel is about 2,333 days.
(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)
It's about one-fifth as long as The American Revolutionary War

The length of The American Revolutionary War is about 3,060 days.
(a.k.a. American War of Independence) (1775-83)
It's about one-fifth as long as King Tut's reign

The length of King Tut's reign is about 3,000 days.
(a.k.a. Tutankhamun, a.k.a. Tutankhaten, a.k.a. tVwa:t-ʕa:nəx-ʔaˡma:n) (1333 BCE - 1324 BCE)
It's about six times as long as The First artificial heart patient's survival
The length of The First artificial heart patient's survival is about 112 days.
(1982) (Dr. Barney Bailey Clark; first permanent, pneumatic device)
It's about six times as long as The Spanish-American War
The length of The Spanish-American War is about 109 days.
(1898)
It's about one-tenth as long as FDR's Presidential Term
The length of FDR's Presidential Term is about 4,422 days.
(a.k.a. Franklin Roosevelt, a.k.a. Franklin Delano Roosevelt) (1933-45)
It's about seven times as long as The First spaceflight (Sputnik)
The length of The First spaceflight (Sputnik) is about 91 days.
(a.k.a. Sputnik 1, a.k.a. Спутник-1, a.k.a. "Satellite-1", a.k.a. Простейший Спутник-1) (1957) (total time in orbit)
It's about nine times as long as Columbus' voyage to America
The length of Columbus' voyage to America is about 70 days.
(1492) (first voyage)
It's about ten times as long as The Voyage of the Mayflower
The length of The Voyage of the Mayflower is about 66 days.
(1620)
It's about thirteen times as long as The First US Continental Congress

The length of The First US Continental Congress is about 51 days.
(1774) (Philadelphia, Pennsylvania)