Byzantine hours

Byzantine time counts the day from local sunset. This app is a local-first calculation aid for showing sunset-anchored equal hours, seasonal or temporal hours when sunrise and sunset are available, and ordinary civil time for the selected place and time zone.

Calculations run in the browser from the selected profile, location, and time zone. The app does not use accounts, ads, tracking cookies, behavioral profiles, background location, or server-side coordinate processing. The live site may use privacy-preserving Cloudflare Web Analytics for aggregate visit and page-view counts.

Generic calendar profiles

The selectable profiles are Generic Old Calendar and Generic New Calendar convenience profiles. They can show limited Orthodox calendar dates and major observances, but they are not named jurisdiction profiles and do not replace parish, monastery, diocesan, or ecclesiastical authority.

Calendar-file export creates a bounded .ics file that can be opened or imported in common calendar apps. Calendar-file import shows downloaded events inside this browser session, but imported files do not change the Byzantine clock, selected profile, location, calendar rules, or prayer-office schedule.

Open-page reminders

In-app reminders are limited to the page while it remains open and active. For alerts outside this page, download a calendar file and let the calendar app handle notifications.

The app does not promise reliable closed-browser reminders, Web Push delivery, native mobile alerts, watch alerts, hosted accounts, payments, or a server-backed reminder service.

Local calculation aid

This is not an official Athonite, parish, monastery, diocesan, or jurisdictional calendar. Calendar and service practices vary by jurisdiction, monastery, parish, calendar usage, and local custom.

Use the app as a local calculation aid, then follow your parish, monastery, bishop, or spiritual father where applicable. JavaScript is required for live solar, clock, calendar, import, export, offline-shell, and reminder controls.