Circa (from Latin, meaning 'around, about, roughly, approximately') – frequently abbreviated ca., or ca and less frequently c.,circ. or cca. – signifies "approximately" in several European languages and as a loanword in English, usually in reference to a date. Circa is widely used in historical writing when the dates of events are not accurately known.
When used in date ranges, circa is applied before each approximate date, while dates without circa immediately preceding them are generally assumed to be known with certainty.
- 1732–1799: Both years are known precisely.
- c. 1732 – 1799: The beginning year is approximate; the end year is known precisely.
- 1732 – c. 1799: The beginning year is known precisely ; the end year is approximate.
- c. 1732 – c. 1799: Both years are approximate.