The Orthodox Church of Ukraine (OCU), backed by Kiev, has announced its plans to potentially adopt a new liturgical calendar. The move would make it closer to the Catholic and Protestant denominations while breaking up with traditions followed by the canonical Ukrainian Orthodox Church (UOC) and the Russian Orthodox Church. The calendar is used to determine the dates of holy days like Christmas or Easter.

According to Ukraine’s Strana.ua news media outlet, the OCU might start celebrating Christmas on December 25 instead of January 7, as it used to under the canonical UOC.

Orthodox churches usually stick to their own Orthodox liturgical calendar, which differs from the Catholic and Protestant ones. Five of them, including the Russian Orthodox Church – the largest Orthodox Church in the world with 150 million worshippers around the globe – as well as Jerusalem, the Serbian, Georgian, and Polish Orthodox Churches, still follow the old Julian calendar. The Catholics and Protestants use the Gregorian calendar, introduced by Pope Gregory XIII in the 16th century. 

The Constantinople Patriarchate, together with 10 other Orthodox churches, adopted the Revised Julian Calendar in the early 20th century. The reform made the dates of all fixed holy days, like Christmas, similar to those of the Catholic Church. Moveable holy days like Easter are still determined in line with the old Julian calendar under this new system.

Now, the OCU wants to adopt the revised calendar, arguing that it is more "accurate." The Kiev-backed church has been "considering the calendar reform and taking relevant steps … for a long time," its head, Metropolitan Epiphany, told Ukraine’s Gazeta.ua media outlet. The final decision is to be made at the bishops’ council in May, he added. 

The reform would allow the OCU to switch to a "more accurate calendar and avoid gradually moving the fixed holy days in the future," he claimed. According to the Ukrainian media, some OCU dioceses adopted the new calendar even before the council’s decision. In Odessa, the local OCU priests announced adopting the new calendar as early as January. 

The move comes amid Kiev’s crackdown on the canonical Ukrainian Orthodox Church. The UOC has historical ties with the Russian Orthodox Church and was accused by Ukrainian officials of being a security threat amid the military conflict with Russia. The Security Service of Ukraine (SBU) has been raiding UOC churches, ostensibly searching for weapon stockpiles and evidence of treason.

Six Ukrainian regions have outright outlawed the UOC on their territory and favored the OCU. Established only in 2018, the OCU has been recognized only by three other Orthodox churches. The UOC considers it heretical.

President Vladimir Zelensky’s government has prepared a bill that would ban the UOC in Ukraine, but the parliament has yet to vote on it. Moscow protested against the persecution of Orthodox Christians by Ukrainian authorities, but none of the human rights bodies in the West have responded so far.