The 20th century began on January 1, 1901, and ended on December 31, 2000. The confusion often arises because the century designation shifts by one year compared to the numbered years. For instance, while the first century spanned from the year 1 to 100, the 20th century covers 1901 through 2000. This system is based on the Gregorian calendar, which is the most widely used calendar today.
The start of the 20th century marked a period of significant global transformations, with massive developments in technology, politics, and culture that shaped the modern world. Understanding these timelines is essential for better grasping historical context and narratives surrounding major events in the 1900s.