To REPLY #44
I'm not a theologian or an expert in this area, but here are my impressions regarding your inquiry. The doctrine of the Orthodox Church comes from the 7 Ecumenical Synods (Councils). The doctrinal statements of these synods became required for the faithfull to believe in order to achieve salvation, once they are accepted by the clergy and faithful of the church, (actually, not rejected), and are considered infallible when ratified by the subsequent synod.
Pronouncements such as the local synodal statements you've identified (they were not conferences of all the hierarchy of the church), have standing for those under the immediate protection of the synods which were represented and took the position, along with other synods which accept the position. The common acceptance of the greater Church, renders positions such as these, something that is considered required to be followed. But still, it is not doctrine. Thus, a subsequent synod can take a modified position.
I would guess that the Churches which follow what we call the "new calendar," would respond to your question by indicating that they are not in non-compliance with these statements because they adopted a Revised Julian Calendar, not the Gregorian Calendar. A Pan Orthodox Congress of a few representatives of each of the Holy Orthodox Churches which attended (at which only the First Throne among the Ancient Patriarchates was represented, as the convener), recommended to the Holy Orthodox Churches the adoption of a Revised Julian Calendar. The Synods of the Churches of Greece, Constantinople, Cyprus, Romania, Alexandria, Antioch, and Bulgaria, eventually adopted the Revised Julian Calendar, while retaining the Julian Calendar for the computation of the Pascal cycle, (except for the Church of Finland which has been given an exception by Economy). The Churches of Jerusalem, Russia, and Serbia, have not changed from the traditional use of the Julian Calendar. Another complication, Churches which use the Revised Julian Calendar may allow eparchies under them use of the Julian Calendar, the Holy Mountain, Mt. Athos, which is under the Ecumenical Patriarchate, being a significant example of that situation.
I would suggest that the Calendar that was used by the First Ecumenical Synod to establish a uniform day for the celebration of Pascha, was not a doctrinal adoption of that calendar; however, the Old Calendarist Churches which are separated from the Holy Orthodox Churches, would submit that the Julian Calendar became the Church Calendar, sanctified by its use.
There could be much more said about this matter, (there is another thread on the calendars on this forum), the primary problem obviously being, that the Church as a whole did not reach a consensus on a pan-Orthodox basis, when the government of Greece coerced the Church of Greece to adopt the new calendar, which pushed the Ecumenical Patriarchate to accordingly change too. So, for the last 85 years, "some fast while others feast" within Orthodoxy (except for the Great Lent/Paschal cycle), also resulting in the phenomenon of separated churches, often referred to as Old Calendar jurisdictions.