The 20th - century events include many notable events which occurred throughout the 20th century , which began on January 1 , 1901 .
The 20th - century events ended on December 31 , 2000 , according to the Gregorian calendar .
The 20th - century events include many notable events which occurred throughout the 20th century , which began on January 1 , 1901 , and ended on December 31 , 2000 , according to the Gregorian calendar .