Related term: bissext, intercalary, bissextile
Etymology: Bissextus is derived from the Latin bissextus dies that means inserting a day. The word is formed by the Latin words bis (“twice”) and sextus (“sixth”). In the old Roman calendar February was the last month of the year. Before Caesar introduced the Julian calendar in 46 BC, the Roman calendar inserted a day after February 24, the sixth day before the Calends of March (March 1).
Intercalary is derived from the Latin word intercalarius, from intercalare, formed by inter (“between”) and calare (“to call”), meaning to proclaim the insertion of an extra day.
Bissextile from the Latin bissextilis means a year containing an intercalary day; a leap year. The Latin term annus bissectus means a bissextile year.
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