Ukraine is moving its Christmas Day holiday to Dec. 25 in defiance of Russia

Ukrainian President Volodymyr Zelenskyy on Friday signed a law moving the official Christmas Day holiday to Dec. 25 from Jan. 7, the day it's observed bythe Russian Orthodox Church.

The explanatory note attached to the law said its goal is to "abandon the Russian heritage," including that of "imposing the celebration of Christmas" on Jan. 7, and cited Ukrainians' "relentless, successful struggle for their identity" and "the desire of all Ukrainians to live their lives with their own traditions, holidays," fuelled by Russia's 17-month-old aggression against the country.

Last year, some Ukrainians already observed Christmas on Dec. 25, in a gesture that represented separation from Russia, its culture and religious traditions.

The law also moves the Day of Ukrainian Statehood to July 15 from July 28, and the Day of Defenders of Ukraine to Oct. 1 from Oct. 14.

The Russian Orthodox Church, which claims sovereignty over Orthodoxy in Ukraine, and some other Eastern Orthodox churches continue to use the ancient Julian calendar. Christmas falls 13 days later on that calendar, or Jan. 7, than it does on the Gregorian calendar used by most church and secular groups.

The Catholic Church first adopted the modern, more astronomically precise Gregorian calendar in the 16th century. Protestants and some Orthodox churches have since aligned their own calendars for the purpose of calculating Christmas and Easter.

Ukraine's religious landscape has fractured for years. There are two branches of Orthodox Christianity in the country, one aligned with the Russian church, even as it enjoys broad autonomy, and the other completely independent of it.

The Orthodox Church of Ukraine, the branch that is separate from the Russian church, announced earlier this year that it was switching to the Revised Julian calendar, which marks Christmas on Dec. 25.

Its leadership last year allowed believers to celebrate the holiday on Dec. 25. Russia's state news agency RIA Novosti reported on Saturday that the rival Orthodox Church, which is aligned with the Russian Orthodox Church, vowed to continue observing Christmas on Jan. 7.

WATCH | Ukrainian newcomers changetheir Christmas traditions:

These Ukrainian newcomers are changing their Christmas traditions

2 years ago

Duration 1:52

Father Taras Kinash of Assumption Of The Blessed Virgin said it doesn't matter which day people decide to celebrate Christmas on. What matters, he said, is the spirit of the holiday.

One year since 'vile and cruel' attack

Zelenskyy on Saturday travelled to the war-torn Donetsk region in eastern Ukraine, which Russia has illegally annexedbut only partially occupies, and met with members of the country's Special Operation Forces.

He noted in an online statement that Saturday marks their official day of recognition and also the anniversary of the deadly attack on the Olenivka prison in the Russian-held part of the region in which dozens of prisoners of war were killed.

Russia and Ukraine accused each other of the attack, with both sides saying that the assault was premeditated in a bid to cover up atrocities.

A United Nations fact-finding mission requested by Russia and Ukraine was sent to investigate the killings, but the team was disbanded in January 2023 due to security concerns.

Zelenskyy described the attack as one of Russia's "most vile and cruel crimes" in a video statement Saturday.