Multilingual structured Old and New Orthodox Calendar dataset for the years 1924–2099.

Application that provides support for Old and New Orthodox Calendar for the years 1924–2099.

Almanac 历

A C implementation of most of the book "Calendrical Calculations".

Early Modern Dates

An Orthodox and Catholic Easter Date Calculator

Convert between Julian day numbers and Julian & Gregorian calendars

A Swift framework containing an astronomical model of the Moon, including properties to obtain the age, percent illuminated, phase, transitions, and other properties of the Moon at a point in time. This is a Swift port of John Walker's `moontool.c`, originally written in 1987.

Julian date calculations and calendar conversions for Swift.

jcalendaR is a package for converting between current Japanese calendar, old Japanese calendar that Kyureki, and Julian and (proleptic) Gregorian calendar in R.

Converts a gregorian date to julian date.

Historic calendars of Europe

The project is a collection of functions to convert dates between Gregorian and Julian calendars. Additionally it includes functions to calculate Orthodox and Catholic Easter dates.

Calendar implementation using object-oriented principles in C++.

An implementation of the Roman calendar post-Julian reforms (46 BC)

Selected development examples from Numerical Recipes in FORTRAN 77

Julian Date gadget for Windows. main branch: https://barionleg.github.io/JulianDate/source/Julian.html

📅 Explore a structured Orthodox Christian liturgical calendar dataset in JSON for 1924–2099, supporting both Julian and Revised Julian calendars.

Open-source Orthodox/Oriental Orthodox saints and name-day service with FastAPI backend, React frontend, ICS feeds, and calendar-aware name-day reminders.

📅 Manage and explore Orthodox calendar dates from Mount Athos, enhancing your spiritual journey with easy access to rich historical content.