Word origin · etymology
English phrase with Latin roots through French.
Civil descends from Latin civilis, related to civis, citizen. Date in its calendrical sense comes through French from Latin data, associated with dating documents. These histories explain the component words; an exact first use of the compound is not established here.
Merriam-Webster · civil, word history ↗Merriam-Webster · date, calendar noun and word history ↗
How we know · epistemology
Declared calendar convention
Calendar rules determine the date label. A date-only tool can operate on that label; an astronomical calculation additionally needs enough information to resolve an instant. Atlas states which kind of input each method uses.
US Naval Observatory · Julian Date Converter, calendar notes ↗Svante Janson · Tibetan calendar mathematics ↗
Connected concepts
Terms used in this explanation
Mentioned in 5 other entries
These links connect subjects and terminology. They do not establish a shared historical origin.
Sources & provenance
Use the citations beside each section to distinguish a calculation convention, a historical teaching and an editorial example.