The Living Calendar
Why You Can Trust the Calendar
The heart of Gedam is a living liturgical calendar, and a calendar is only as good as it is correct. Here is how Gedam’s is built and proven, in plain terms.
It is computed, not copied
Gedam does not store a fixed list of dates for a single year. It calculates the calendar from the Church’s own rules, so that it is correct in any year you open: past, present, or future.
It follows each church’s own reckoning
The Oriental Orthodox do not all keep one Easter. The Coptic, Ethiopian, and Eritrean churches follow the ancient Alexandrian calculation, and the Syriac Orthodox Church keeps that same older (Julian) Pascha; only the Armenian and Malankara churches keep the modern Easter. Gedam computes both and applies the right one to each tradition. From Easter flow all the movable observances of the year: the Fast of Nineveh, Great Lent, Palm Sunday, the Resurrection, the Ascension, and Pentecost. The thirteen-month Coptic and Ethiopian calendar is converted to the common calendar exactly, so feasts such as Genna and Timkat fall on the right day every year, including the years when they shift by a day. Each church’s fasts are kept at that church’s own lengths, not borrowed from another.
It is tested
The calculations are checked against the churches’ own published calendars and against the known dates of Easter across many years; the Geʼez calendar is checked against fixed reference points; and the whole calendar is run across entire years to confirm that every single day resolves correctly. Where two independent editions of a church’s readings exist, they are cross-checked against one another. Errors found in source materials are corrected against the Church’s own published texts before anything is shown.
It is honest
Where a finer rule is genuinely uncertain, Gedam does not guess; it asks the Church. Anything still being confirmed is noted rather than presented as settled.
For those who wish to know more, the full method and the record of testing are documented and can be shared on request; write to [email protected].
An honest word
If a date looks wrong, please tell us
Six churches, two Paschal cycles, a thirteen-month calendar, and fasts that each tradition keeps at its own length. Putting this together is genuinely difficult work, and we have treated it that way.
- Pascha, the anchor of the whole movable year, computed and matched against the published Orthodox dates for every year from 2024 through 2030. No mismatches.
- The Armenian, Syriac, and Malankara churches computed from their own Easter across 2024 to 2033, never borrowed from the Alexandrian cycle. No mismatches.
- Every single day of a full year resolved for all six traditions: 2,190 checks for 2026 and 2,196 for the leap year 2028, with no failures in either.
- Each tradition’s fasts checked for start, end, and length from 2025 through 2033 against that church’s own published calendars.
- All 10,364 Scripture references in the lectionary resolved and verified against the source.
- The Geʼez conversion anchored to fixed points: Enkutatash, Genna, and Timkat, including the years they shift by a day.
That testing found real errors, and every one of them was corrected. Eleven broken Scripture references. Three churches quietly receiving another church’s Pascha. Coptic and Ethiopian feasts drifting by a day near leap years. The Wednesday and Friday fast not being lifted on the Nativity and Theophany. We would rather say that plainly than suggest the work came out clean the first time.
Some things remain open. A few finer Tewahedo and Coptic fast-free rules are waiting on an answer from clergy. Two Armenian week-fasts have no published computus, so they are left out rather than guessed at. Where we are not certain, we say so instead of filling the gap.
Gedam is being tested now, before launch, with people from each of the six churches. If you open it and a fast begins on the wrong day, a feast is missing, or the saint is not the one your church commemorates, write to [email protected]. Tell us your church and the date, and we will look into it. A correction from someone who keeps the calendar in their own parish is worth more than anything we can compute on our own, and every one of them makes Gedam better for the whole community.
Every reading, cited
The calendar is computed. The content is sourced.
Every fast, feast, reading, and saint is drawn from a cited source and never written from memory. See where it all comes from.
View the sources