@magmacomputing/tempo-plugin-roman

A lightweight, zero-dependency Tempo community plugin providing classical Roman calendar arithmetic (Kalends, Nones, Ides, Ante Diem), leap year bissextile handling, and AUC (Ab Urbe Condita) year conversions.

⚡ Classical Roman Calendar Mechanics

Ancient Roman timekeeping operated backwards from three lunar anchor points:

• Kalends (Kalendae): 1st of every month.
• Nones (Nonae): 7th in "MOM-J" months (March, October, May, July); 5th in all others.
• Ides (Idus): 15th in "MOM-J" months; 13th in all others.
• Pridie: The day immediately preceding an anchor (e.g. Pridie Idus Octobres = October 14).
• Ante Diem: Inclusive backward counting from an anchor (e.g. Ante diem XVII Kalendas Novembres = October 16).
• Bissextile Day: Doubling of the 6th day before the March Kalends (ante diem bis sextum Kalendas Martias, February 24 in leap years).
• AUC (Ab Urbe Condita): Years reckoned from the traditional founding of Rome in 753 BCE ($2026 \text{ CE} \implies 2779 \text{ AUC}$, $44 \text{ BCE} \implies 710 \text{ AUC}$).

📦 Installation

npm install @magmacomputing/tempo-plugin-roman

📦 Import Paths & Bundle Options

Choose the import path that best fits your application's size and feature requirements:

| Import Path | Minified Size | What's Included | | :--- | :--- | :--- | | import '@magmacomputing/tempo-plugin-roman/install' | ~15 KB | Full Roman calendar arithmetic, Latin phrasing/parsing, AUC conversions, and ~20 landmark consul years (Cicero, Caesar, Brutus, Basilius). Auto-installs plugin. | | import '@magmacomputing/tempo-plugin-roman/consuls' | ~70 KB | Batteries-included: full Roman calendar plugin + complete 1,050-year Fasti consulares catalog (509 BCE–541 CE). Auto-installs plugin in one import. | | import { RomanPlugin } from '@magmacomputing/tempo-plugin-roman' | ~15 KB | Core plugin definition for explicit installation via Tempo.use(RomanPlugin). |

🚀 Quick Start

Option A: Lean Core Plugin (Zero-Boilerplate)

import '@magmacomputing/tempo-plugin-roman/install';
import { Tempo } from '@magmacomputing/tempo';

// 1. Classical Roman calendar arithmetic & Latin phrasing
const t = new Tempo('2026-10-16');
const roman = t.toRomanClassical();
console.log(roman.latin);      // "ante diem XVII Kalendas Novembres"
console.log(roman.shortLatin); // "a.d. XVII Kal. Nov."
console.log(roman.auc);        // 2779 (AUC)

// 2. Ides of March (44 BCE = astronomical year -43)
const idesOfMarch = new Tempo('-000043-03-15');
console.log(idesOfMarch.toRomanClassical().latin); // "Idibus Martiis"
console.log(idesOfMarch.consuls);                  // "C. Julio Caesare V, M. Antonio coss."

// 3. Leap year bissextile day (February 24 in leap year)
const leapDay = new Tempo('2024-02-24');
console.log(leapDay.toRomanClassical().latin); // "ante diem bis sextum Kalendas Martias"

Option B: Full Consular Catalog (Single Import)

If you need the entire historical Fasti covering all 1,050 years from 509 BCE through 541 CE:

import '@magmacomputing/tempo-plugin-roman/consuls';
import { Tempo } from '@magmacomputing/tempo';

// Resolves any year across the Republic and Empire
const trajan = new Tempo('0100-01-01');
console.log(trajan.consuls);
// "Imp. Caesare Nerva Trajano Augusto III, Sex. Julio Frontino III coss."

Option C: Explicit Installation

import { Tempo } from '@magmacomputing/tempo';
import { RomanPlugin } from '@magmacomputing/tempo-plugin-roman';

Tempo.use(RomanPlugin);

📖 Static Utilities (Tempo.roman)

The plugin exposes pure calculation functions directly under Tempo.roman:

import { Tempo } from '@magmacomputing/tempo';
import '@magmacomputing/tempo-plugin-roman/install';

// AUC Conversion
Tempo.roman.yearToAuc(2026);              // 2779
Tempo.roman.yearToAuc(44, 'BCE');         // 710
Tempo.roman.aucToYear(710, 'historical'); // { year: 44, era: 'BCE' }

// Round-trip Gregorian from Roman anchor
const date = Tempo.roman.fromClassical('Kalends', 11, 2026, 'ante_diem', 17);
console.log(date); // { year: 2026, month: 10, day: 16 }

// Consular dating formula (landmark seed table available by default)
const cicero = new Tempo('-000062-03-15');
console.log(cicero.consuls); // "M. Tullio Cicerone, C. Antonio Hybrida coss."

📜 License

MIT © Magma Computing