calendar's adoption by Orthodox churches. The matter came up for discussion at a "Pan-Orthodox" Congress of Constantinople, which deliberated in May and June. Subsequently, it was adopted by several of the autocephalous Orthodox churches. The synod was chaired by the controversial patriarch and representatives were present from the churches of Cyprus, Greece, Romania and Serbia. There were no representatives of the other members of the original Orthodox Pentarchy (the Patriarchates of Jerusalem, Antioch, and Alexandria) or from the largest Orthodox church, the Russian Orthodox Church. Discussion was lengthy because although Serbia officially supported the political calendar, Milanković (an astronomical delegate to the synod representing the Kingdom of Serbs, Croats and Slovenes) pressed for the adoption of his own version, in which the centennial leap years would be those giving remainder 200 or 600 when divided by 900 and the equinox would generally fall on 20 March (as in the Gregorian). Under the official proposal the equinox would sometimes fall on 22 March. This might make Easter fall outside its canonical limits due to the requirement that the Easter full moon follow the equinox. Also his scheme maximised the time during which the political calendar and the Gregorian would run in tandem. Milanković's arguments won the day. In its decision the conference noted that "the difference between the length of the political year of the new calendar and the Gregorian is so small that only after 877 years it is observed difference of dates." The same decision provided that the coming should be called , thus dropping thirteen days. It then adopted the leap year rule of Milanković. The political calendar was preferred over the Gregorian because its mean year was within two seconds of the then current length of the mean tropical year. The present vernal equinox year, however, is about 12 seconds longer, in terms of mean solar days. The synod also proposed the adoption of an astronomical rule for Easter: Easter was to be the Sunday after the midnight-to-midnight day at the meridian of the Church of the Holy Sepulchre in Jerusalem (35°13′47.2″ E or UT+22055 for the small dome) during which the first full moon after the vernal equinox occurs. Although the instant of the full moon must occur after the instant of the vernal equinox, it may occur on the same day. If the full moon occurs on a Sunday, Easter is the following Sunday. Churches