January 31st is the 31st day of the year in the Gregorian calendar. There are 334 days remaining until the end of the year (335 in leap years). This date is slightly more likely to fall on a Tuesday, Thursday or Sunday (58 in 400 years each) than on Friday or Saturday (57), and slightly less likely to occur on a Monday or Wednesday (56).
1616 – Gunpowder Plot: Guy Fawkes is executed for plotting against Parliament and King James.
1865 – The United States Congress passes the Thirteenth Amendment to the United States Constitution, abolishing slavery and submits it to the states for ratification.
1915 – Germany is the first to make large-scale use of poison gas in warfare in the Battle of Bolimów against Russia.
1950 – United States President Harry S. Truman announces a program to develop the hydrogen bomb.
2001 – In the Netherlands, a Scottish court convicts Libyan Abdelbaset al-Megrahi and acquits another Libyan citizen for their part in the bombing of Pan Am Flight 103 over Lockerbie, Scotland in 1988.
Scandal Actress Kerry Washington turns 41
Singer-Songwriter Justin Timberlake turns 37
Actress and Model Portia de Rossi turns 45
Florida Georgia Line Musician Tyler Hubbard turns 31
Saturday Night Live Actor Bobby Moynihan turns 41