A decade is a period of 10 years. The word is derived (via French) from the Ancient Greek dekas which means ten. This etymology is sometime confused with the Latin decas (ten) and dies (days), which is not correct.[1] The other words for spans of years come from Latin: lustrum (5 years), century (100 years), millennium (1000 years).



Although any period of 10 years is a decade,[2][3] a convenient and frequently referenced interval is based on the tens digit of the calendar year, as in using "1960s" to represent the decade from 1960 to 1969.[4][5] Often, for brevity, only the tens part is mentioned (60s or sixties), although this may leave it uncertain which century is meant. These references are frequently used to encapsulate popular culture or other widespread phenomena that dominated such a decade, as in The Great Depression of the 1930s.

Since the common calendar starts from the year 1, its first full decade contained the years from 1 to 10, the second decade from 11 to 20, and so on.[6] So while the "1960s" comprises the years 1960 to 1969, the "197th decade" spans 1961 to 1970.

A decade may also refer to an arbitrary span of 10 years. For example, the statement "during his last decade, Mozart explored chromatic harmony to a degree rare at the time," merely refers to the last 10 years of Mozart's life without regard to which calendar years are encompassed.

Thus, an unqualified reference to, for example, "the decade" or "this decade" may have multiple interpretations depending on the context.

See also


  1. ^ Larousse, etymology of decade(French)
  2. ^ Oxford dictionary definition of "decade"
  3. ^ Webster dictionary definition of "decade"
  4. ^ The OWL at Purdue: Apostrophe
  5. ^ "1960s". Memidex/Wordnet Dictionary/Thesaurus. Retrieved 2011-08-18. 
  6. ^ Passim, i.a. Spencer, Donald D. 1989. Invitation to number theory with Pascal. Ormond Beach: Camelot. 46: "The first decade is from 1 to 10 inclusive, the second decade from 11 to 20 inclusive, and so on."

External links