Charles Fort: A Fortean Chronology, 1917.

Year 1917 (MCMXVII) was a common year starting on Monday of the Gregorian calendar.

January

• January 11: German saboteurs set off the Kingsland Explosion at Kingsland, NJ (now Lyndhurst, NJ).
• January 19: Silvertown explosion: A blast at a munitions factory in London kills 73 and injures over 400.
• January 25: The Danish West Indies is sold to the United States for $25 million.
• January 26: The sea defences at the English village of Hallsands are breached, leading to all but one of the houses becoming uninhabitable.
• January 30: Pershing's troops in Mexico begin withdrawing back to the United States. They reach Columbus, Ohio February 5.

February

• February 3: World War I. The United States breaks off diplomatic relations with Germany.
• February 13: Mata Hari is arrested for spying.
• February 24: World War I: United States ambassador to the United Kingdom, Walter H. Page, is shown the intercepted Zimmermann Telegram, in which Germany offers to give the American Southwest back to Mexico if Mexico declares war on the United States.

March

• March 1: The U.S. government releases the plaintext of the Zimmermann Telegram to the public.
• March 1: Japanese city of Omuta, Fukuoka is founded by Hiroushi Miruku
• March 2: The enactment of the Jones Act grants Puerto Ricans United States citizenship.
• March 4: U.S. President Woodrow Wilson begins his second term.
• March 4: Jeannette Rankin of Montana becomes the first woman member of the United States House of Representatives.
• March 8: The Russian 'February' Revolution begins with the overthrow of the Tsar.
• March 15: Tsar Nicholas II of Russia abdicates his throne for his son. Grand Duke Michael Alexandrovich of Russia refuses the throne.
• March 26: World War I. First Battle of Gaza, British cavalry troops retreat after 17,000 Turks block their advance.
• March 30: The independence of Poland is recognized.

April

• April 6: World War I: The United States declares war on Germany.
• April 10: An ammunition factory explosion in Chester, Pennsylvania kills 133.
• April 15: A short lived spot upon the sun, unlike any sunspot he had ever seen, is observed by Col. Markwick. (Books521)
• April 16: Vladimir Lenin arrives in Petrograd.
• April 19: The Second Battle of Gaza, a fiasco for the British, causes the dismissal of the commander of the Eastern Expeditionary Force, General Archibald Murray.

May

• May 13: Three peasant children claim to see the Virgin Mary above a Holm Oak tree in Cova da Iria near Fátima, Portugal.
• May 18: World War I: The Selective Service Act passes the U.S. Congress, giving the President the power of conscription.
• May 21: Over 300 acres (73 blocks) are destroyed in the Great Atlanta fire of 1917.
• May 23: A month of civil violence in Milan, Italy ends after the Italian army forcefully takes over the city from anarchists and anti-war revolutionaries. Fifty people are killed and 800 people are arrested.
• May 26: A tornado strikes Mattoon, Illinois, causing devastation and killing 101 people.
• May 27: Over 30,000 French troops refuse to go to the trenches in Missy-aux-Bois.

June 

• June 1: A French infantry regiment seizes Missy-aux-Bois and declares an anti-war military government. Other French army troops soon apprehend them.
• June 5: World War I, Conscription begins in the United States.
• June 13: World War I, The first major German bombing raid on London leaves 162 dead and 432 injured.
• June 15: The United States enacts the Espionage Act.

July

• July 1: A labor dispute ignites a race riot in East St. Louis, Illinois, which leaves 250 dead.
• July 4: An eclipse of the sun, an extraordinary luminous object, said to be a meteor, is seen over France. (Books521)
• July 4: At Colby, Wisconsin, USA, a stone fell from the sky. (Books521)
• July 6: Arabian troops led by T. E. Lawrence capture Aqaba from the Turks.  
• July 16-17: Russian troops mutiny, abandon the Austrian front, and retreat to the Ukraine; hundreds are shot by their commanding officers during the retreat.
• July 16-18: Serious clashes in St. Petersburg in July Days; Lenin escapes to Finland; Trotsky is arrested.
• July 20: Finland declares complete independence.
• July 20: The Corfu Declaration, which enabled the establishment of the post-war Kingdom of Yugoslavia, is signed by the Yugoslav Committee and the Kingdom of Serbia.  
• July 31: World War I. Third Battle of Ypres or the Battle of Passchendaele: Allied offensive operations commence in Flanders.

August

• The Green Corn Rebellion, an uprising by several hundred farmers against the World War I draft, takes place in central Oklahoma.
• August 10: A general strike begins in Spain; it is smashed after 3 days with 70 left dead, hundreds of wounded and 2,000 arrests.
• August 17: One of English literature's important meetings takes place when Wilfred Owen introduces himself to Siegfried Sassoon at the Craiglockhart War Hospital in Edinburgh.
• August 18: The Great Thessaloniki Fire of 1917 in Greece destroys 32% of the city, leaving 70,000 individuals homeless.
• August 19. A luminous object is seen moving upon the moon. (Books521)

October

• October 12: World War I. The biggest loss of life in a single day for New Zealand. Over 800 men and 45 officers were killed at the first Battle of Passchendaele, roughly 1 in 1000 of the nations population at the time.
• October 15: World War I. At Vincennes outside of Paris, Dutch dancer Mata Hari is executed by firing squad for spying for Germany.
• October 25: Traditional beginning date of the Bolshevik Revolution.
• October 26: World War I. Brazil declares war against the Central Powers.

November

• World War I: Third Battle of Gaza. United Kingdom forces capture Gaza from the Ottoman Empire.
• November 6: World War I. Third Battle of Ypres: After 3 months of fierce fighting, Canadian forces take Passchendaele in Belgium.
• November 7: October Revolution, The workers of Petrograd in Russia, led by the Bolshevik leader Vladimir Lenin, attack the Kerensky Provisional Government.
• November 15: In the United States, a "Night of Terror" results in the death of several influential suffragettes.  
• November 23: The Bolsheviks release the full text of the previously secret Sykes-Picot Agreement in Izvestia and Pravda; it is subsequently printed in the Manchester Guardian on November 26.
• November 24: In Milwaukee, Wisconsin, 9 members of the Milwaukee Police Department are killed by a bomb.
• November 28: The Bolsheviks offer peace terms to the Germans.

December

• December 6:  Halifax Explosion. Two freighters collide in Halifax Harbour at Halifax, Nova Scotia and cause a huge explosion that kills at least 1,963 people, injures 9,000 and destroys part of the city.
• December 11: British troops take Jerusalem from the Ottoman Empire.