Putin ordered the ceasefire to begin on Jan. 6, the Kremlin said. Many Orthodox Christians, including those living in Russia and Ukraine, celebrate Christmas on Jan. 6-7.
Patriarch Kirill of Moscow called earlier on Thursday for both sides of the war in Ukraine to observe a Christmas truce.
"Taking into account the appeal of His Holiness Patriarch Kirill, I instruct the Minister of Defence of the Russian Federation to introduce a ceasefire regime along the entire line of contact of the parties in Ukraine from 12.00 on January 6, 2023 to 24.00 on January 7, 2023," Putin said in the order.
Ukraine spurned Putin's offer for a 36-hour ceasefire over Orthodox Christmas, saying there would be no truce until Russia withdraws its invading forces from occupied land.
Russia's Orthodox Church observes Christmas on January 7. Ukraine's main Orthodox Church has rejected the authority of the Moscow patriarch, and many Ukrainian believers have shifted their calendar, celebrating Christmas on December 25 as in the West.