"People here have long insisted we should be united around a common festival, expressing our faith together and enjoying the same work-free days," explained Auxiliary Bishop Jan Sobilo of Ukraine's eastern Kharkiv-Zaporizhzhia Diocese.

"As we withstand Russia's attacks, however, this change will also have a political dimension in bringing us closer to Western civilization. Many of those who no longer attend church, believing Christians are always feuding, may well be led back to God by this new united spirit of prayer and celebration," he said.

The bishop spoke to OSV News amid preparations for the long-awaited switch to the Western Christmas, agreed earlier in 2023 by church and government leaders.

Meanwhile, a prominent Greek Catholic priest told OSV News he expected little need for liturgical modifications and also was hopeful the reform would assist common worship with other denominations.

"The traditions will remain the same, and we're planning to do everything as in the past -- just in late December rather than January," said Father Mykola Matwijiwskyj, apostolic administrator of Britain's London-based Greek Catholic eparchy.

"The Western calendar has already been used for years in much of the Ukrainian Catholic diaspora, and this formal change has been accepted by Ukrainians at home and abroad," he said.

A resolution confirming the calendar reform was passed July 14 by Ukraine's Verkhovna Rada parliament and signed into law by President Volodymyr Zelenskyy -- both justifying it as a step toward "abandoning the Russian heritage."

But the move had been long sought by Ukraine's Greek Catholic and independent Orthodox churches in cooperation with Roman Catholics and Protestants, as key to Christian unity in the war-ravaged country.

While Ukraine's rival Moscow-linked Orthodox Church, the UOC, hasn't endorsed the change, opinion polls have shown general support nationwide.

"Those who are pro-Russian will no doubt stay that way -- but we've always invited everyone to our Christmas celebrations, and this won't change," Bishop Stanislav Szyrokoradiuk of Odesa-Simferopol told OSV News Nov. 13.

"We're proclaiming and formalizing something that's already widely practiced anyway, which will assist our relations with Orthodox Christians. Although we can't know how opponents might react, I'm confident most Ukrainians will accept it positively."

Whereas Catholics and Protestants traditionally celebrate Christmas Dec. 25, according to the Western Gregorian Calendar established in 1582 by Pope Gregory XIII, 11 of the world's 15 main Orthodox churches mark it on Jan. 7, in line with the ancient Julian Calendar introduced by Julius Caesar in 46 B.C.E.

Orthodox hierarchies in Bulgaria, Cyprus, Greece and Romania switched during the 20th century to the Western date, along with the based Ecumenical Patriarchate which traditionally holds the Orthodox primacy.

But Russia's powerful Orthodox Church, which seeks to continue dominating Ukraine, still clings to the Eastern system, along with other smaller churches.

Both Dec. 25 and Jan. 7 have been official state holidays in Ukraine since 2017, in recognition of the large numbers celebrating Christmas on both dates. But calls for a general move to Dec. 25 grew after Russia's bloody February 2022 invasion.

Greek Catholics confirmed the switch to Dec. 25 at a synod meeting in February, adopting the new dating system for all fixed religious feast-days, while Metropolitan Epiphany's OCU followed suit in May, a year after the Ukrainian Orthodox Church announced its full independence and autonomy from the Moscow Patriarchate.

And while some parishes will be allowed to opt out and retain the old Julian Calendar initially, Major Archbishop Sviatoslav Shevchuk of Kyiv-Halych insists support for the change has gathered momentum during the war.

"We want the calendar to unite, rather than divide us, giving a new perspective for our church, state and liturgical and social life," the archbishop told church members in a February open letter.

With the change applying to Ukrainian communities worldwide, Father Matwijiwskyj, the London-based Greek Catholic administrator, is confident the change is for the better, both in spiritual and economic terms for the war-torn country.

In the past, the Gregorian Calendar was resisted by some Ukrainian diaspora Catholics, who feared it would compel their assimilation into Western Christianity.

Two years of war have changed perspectives, and Westernization is now the desired option -- although rejecting Russian domination tells only part of the story, Father Matwijiwskyj said.

"While the reform has been pushed through with this in mind, the change will have wider advantages," the priest told OSV News.

"The whole world closes down on Dec. 23 and reopens in early January, while Ukraine then closes down on Jan. 5 and stays that way for much of the month. Correcting this anomaly will have obvious benefits, quite apart from shaking off Russian influences," he explained.

Bishop Sobilo agreed and told OSV News that "although there are constant dangers of escalation, as brutal new attempts are made to break our country this winter, we can be confident about our future as we draw closer to Europe and raise our heads again."

Even in such harsh conditions, Ukrainians have shown determination in maintaining their Christmas customs.

The great festival of Vigilia, or Christmas Eve, is marked with family gatherings around a sviata vechera, or "holy supper," incorporating a dozen dishes representing the 12 apostles, and ends with midnight Mass.

Homes are decorated with the customary didukh, a sheaf of wheat stalks symbolizing ancestors' spirits, for whom dishes such as the traditional kutia are left on the table.

Despite Russian missile strikes, Ukraine's tradition of door-to-door caroling has continued as well, often featuring the internationally known "Carol of the Bells," dating from 1914, and originally written by Ukrainian Mykola Dmytrovych Leontovych.

"People are doing all they can to keep these traditions alive, while the idea of a common Christmas has been warmly accepted as a clear sign of Ukraine's reunion with the Western world," Iryna Biskub, a Catholic linguistics professor at Volyn National University, told OSV News.

"It may be too soon to talk of some major new Catholic-Orthodox ecumenical closeness. But many Orthodox Christians were already marking Christmas with the rest of Europe on Dec. 25, even before this was officially approved," she said. "It's certainly a symbolic move, with strong anti-Russian implications."

In Odesa, Bishop Szyrokoradiuk is confident Ukraine's "beautiful Christmas traditions" are too strongly rooted to be deterred by war and occupation.

The new common Christmas, he thinks, will mark an important step toward reconciliation between people once divided by the East-West Iron Curtain.

A year ago, Moscow rejected calls from European churches for a Christmas truce in its brutal invasion, and even stepped up attacks on Ukraine's population centers.

Against such a background, Ukraine's church leaders will be preparing vibrant Christmas messages of encouragement and endurance.

"Despite the many dead and wounded, people remain strong in spirit and certain of victory -- even if more modestly, they'll still be praying and celebrating at Christmas," Bishop Sobilo told OSV News.