2019-6-28 · The 1900s (pronounced "nineteen-hundreds") was a decade of the Gregorian calendar that began on January 1, 1900, and ended on December 31, 1909. The term "nineteen-hundreds" can also mean the entire century 1900–1999 years beginning with a 19 (see 1900s).The Edwardian era (1901–1910) covers a similar span of time.