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

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. It cited Ukrainians’ “relentless, successful struggle for their identity” and “the desire of all Ukrainians to live their lives with their own traditions, holidays,” fueled 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, continues 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, 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.

Russian President Vladimir Putin told reporters Saturday that the move “is a sign of something that has been happening for centuries” and that “has to do with the relations between the Catholic church and the Orthodox one.”

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

In a separate Telegram statement, he hailed the soldiers in the Donetsk region for “bringing closer the day when all our land and all our people will be free from the occupiers” and underscored the Special Operations Forces’ role in the recent retaking of the village of Staromaiorske in the area.

His visit to the east comes just days after Western and Russian officials said that Kyiv’s forces intensified attacks in the southeast of the country as part of Ukraine’s counteroffensive.

Putin said Saturday that the intensity of Ukrainian attacks along the front line has gone down “compared to two days ago.” He reiterated that Russian forces are successfully repelling all attacks and in some parts of the front line are even mounting successful counteroffensive operations. 

Russian forces on Friday struck the central Ukrainian city of Dnipro and pounded, Staromaiorske, a key village in the southeast that Ukraine claimed to have recaptured in its grinding counteroffensive, while Moscow accused Kyiv of firing two missiles at southern Russia and wounding 20 people.

The Russian missile attack in Dnipro wounded nine people in the area of a newly constructed and as yet unoccupied 12-story apartment building, as well as an unoccupied adjacent Security Service of Ukraine building.

“Russian missile terror again,” Zelenskyy wrote on social media.

Video showed the apartment building’s upper floors in ruins, with gray smoke billowing from them, and flames raging in the night at ground level, where shattered concrete and glass littered a courtyard.

“Windows were blown out right in front of my eyes,” one man told Reuters.

Margarita Sukhova, who owns an apartment on the ninth floor of the apartment building, told CBS News her husband was doing renovations in the apartment only one hour before the attack.

“I am shocked,” Sukhova said…”I hate this country (Russia), this people, they do nothing, they are just sitting watching TV, listening to their propaganda.”

Russia has often struck apartment buildings during the conflict, while denying it intentionally targets civilians.

The Security Service building has been targeted twice before. Dnipro’s mayor said it has been largely empty for months.

The Russian Defense Ministry said it shot down a Ukrainian missile in the city of Taganrog, about 24 miles east of the border with Ukraine, and local officials reported 20 people were injured, identifying the epicenter as an art museum.

Meanwhile, Ukraine’s military released footage Saturday of troops storming Russian trenches on the eastern front line near Bakhmut.

The priority though for Ukrainian forces is to push south from the Zaporizhzhia region to the sea of Azov, which is a nearly 100-mile stretch. If successful, Ukraine would cut off Russia’s land access to Crimea.