Old Calendarists are groups of Orthodox Christians who are in
various levels of "resistance" against the mainstream Orthodox
churches, identified mainly by their insistence on the use of
the Julian Calendar. They are to be distinguished from the
mainstream churches which simply follow the Julian Calendar yet
remain in full communion with most or all of world Orthodoxy.
Many Old Calendarists today say that their concerns about
ecumenism are more significant than calendar issues. The
mainstream churches have varying positions on different Old
Calendarist churches, ranging from an active desire to restore
unity to a denial of the Old Calendarists' Orthodoxy. Some Old
Calendarist groups are styled as True Orthodox or Genuine
Orthodox, and both terms are used in this article. In 1924, the
bishops of the Church of Greece implemented the calendar change
discussed at the pan-Orthodox congress. Afterwards, the former
Primate of the Church of Greece, Germanos of Demetrias, retired
in protest. Lay groups and brotherhood