We divide our time up into regular blocks. Seconds, minutes, hours, days, weeks, months, years, decades, centuries, millennia.
When does one block end and the next start? With most of our divisions of time, the decision is arbitrary. January 1 is arbitrary. The start of a new decade, or a new century, is decided by the year we have arbitrarily decided to call Year 1 AD.
So much might be obvious. The decade of the 1980s is only as valid as the decade 1984–1993. The 20th century is only as extant as the century running 1873–1972.
But we attach things to our arbitrary periods of time. The 1940s was a decade of war; the 1970s was the decade of disco. The fifteenth century was the last in the era of knights and maidens; the sixteenth was the first in the era of art and science.
All this raises an interesting question. What would the decade 1975–84 look like? Would this decade capture the disco of the 70s, or the hair of the 80s? What would the century 1850–1950 look like? Would this be the century of world war — in which case we have lived not 12, but 62 years since that violent century?
Let’s call that decade the 75s, and that century the 19.5th century. Write in and tell me what these new unexplored decades would look like.