The Unification Act (Ukrainian: Акт Злуки, romanized: Akt Zluky, IPA: [ˈɑkt ˈzlukɪ]; or Велика Злука, Velyka Zluka, IPA: [ˈwɛlɪkɐ ˈzlukɐ]) was an agreement signed by the Ukrainian People's Republic and the West Ukrainian People's Republic in Sophia Square in Kyiv on 22 January 1919. Since 1999, it is celebrated every year as the Day of Unity of Ukraine to commemorate the signing of the treaty; it is a state holiday in Ukraine, though not a public holiday.
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