De architectura carries no internal date, and scholarly estimates for when Vitruvius composed the work span roughly 30 to 15 BC. This atlas records a formulated-year using a plain Gregorian Int column, and the house voice convention keeps BC-era dates in prose rather than forcing them into that integer field, so no defensible single year can be written there for this ancient concept.
What would resolve this A narrower scholarly consensus date for the composition of De architectura, or a dedicated atlas convention for recording circa BC dates outside the plain Int column, would let this fact be written honestly instead of left blank.
Resolution The formulation year is recorded as circa 25 BC, the midpoint of the "30 and 20 BC" range Wikipedia's De architectura article states, cited to the same article. The precise year within that range remains unattested; this resolves the column-convention gap the question named, not a claim that the exact year is now known. · 09/11/2026 12:00:00 AM
ResolvedClassical scholarship, architectural historyMarcus Vitruvius Pollio, translated by Morris Hicky Morgan, The Ten Books on Architecture