leap day is the significant event each year that is calculated off the julian calendar.
what significant event each year is calculated off the julian calendar?
leap day
the determination of leap years in the proleptic julian calendar (in either numbering) is distinct from the question of which years were historically considered leap years during the roman era, due to the leap year error: between 45 bc and ad 8, the leap day was somewhat unsystematic. thus there is no simple way to find an equivalent in the proleptic julian calendar of a date quoted using either the roman pre-julian calendar or the julian calendar before ad 8. the year 46 bc itself is a special case, because of the historical introduction of the julian calendar in that year, it was allotted 445 days. before then, the roman republican calendar used a system of intercalary months rather than leap days.
proleptic julian calendar
against the new calendar, the argument is made that inasmuch as the use of the julian calendar was implicit in the decision of the first ecumenical council at nicaea (325), no authority less than an ecumenical council may change this decision. however, the fact is that that council made no decision or decree at all concerning the julian calendar. its silence constituted an implicit acceptance not of the julian calendar, but of the civil calendar, which happened to be, at that time, the julian calendar (the explicit decision of nicaea being concerned, rather, with the date of easter). by virtue of this, defenders of the new calendar argue that no decision by an ecumenical council was or is necessary today in order to "revise" (not abandon) the julian calendar; and further, that by making the revision, the church stays with the spirit of nicaea i by keeping with the civil calendar in all its essentials—while conversely, failure to keep with the civil calendar could be seen as a departure from the spirit of nicaea i in this respect. lastly, it is argued that since the adoption of the new calendar evidently involves no change in or departure from the theological or the ethical teachings of orthodox christianity, but rather amounts to a merely disciplinary or administrative change—a clock correction of sorts—the authority to enact that change falls within the competency of contemporary, local episcopal authority. implicit acceptance of this line of reasoning, or something very close to it, underlies the decision to adopt the new calendar by those orthodox churches that have done so.
revised julian calendar