HTOC Calendar

An HTOC-based Orthodox calendar library. Its published day data comes from the Holy Trinity Orthodox Church calendar in Jordanville; cycle-based output for other years is inferred from that HTOC corpus.

What it provides

• HTOC commemorations and saint lists
• Daily header text, liturgical season, and tone
• Troparia and kontakia
• HTOC daily lectionary readings and date-keyed saint readings
• Julian/Gregorian conversion and Orthodox Pascha calculations used by the HTOC cycle tables

The vendored HTOC corpus covers 2025–2030. The cycle composers extend selected fields beyond those years; see LIMITATIONS.md for where the data is exact and where it is inferred.

Install

npm install htoc-calendar

Usage

import { getHtocDay, getSaintsForAnyYear, orthodoxPascha } from "htoc-calendar";

const day = getHtocDay({ year: 2026, month: 9, day: 27 });
day.headerText;
day.saints.map((saint) => saint.text);
day.dailyReadings;
day.saintReadings; // null when outside the 2025–2030 HTOC corpus

orthodoxPascha(2026); // { year: 2026, month: 4, day: 12 }
getSaintsForAnyYear({ year: 2033, month: 1, day: 7 });

getHtocDay returns HTOC-facing data only. It does not return Ponomar IDs, lives, fasting rules, or service-composition results.

Development

Requires Node.js 20 or newer.

npm install
npm run typecheck
npm test
npm run build

npm run scrape:htoc updates the local HTOC scrape inputs. Generated cycle data is committed; the published build contains only the HTOC API dependency graph.

Data source and licensing

HTOC-derived data is sourced from holytrinityorthodox.com. This project does not imply that HTOC grants a particular redistribution license; confirm data-use rights before redistributing the corpus. The implementation's license is recorded in LICENSE.