Republic Day is celebrated every year on October 29th in Türkiye and Northern Cyprus to commemorate the declaration of the Republic by the Grand National Assembly of Türkiye on October 29, 1923. It is a national holiday that is celebrated.

On October 29th, celebrations are held in stadiums, and in the evening, lantern parades are traditionally organized.

A law passed in 1925 declared the day of the proclamation of the Republic as the national holiday of the new Turkish State.

Mustafa Kemal Atatürk, the founder of the Republic of Türkiye, in his 10th Anniversary Speech given on October 29, 1933, during the celebrations of the tenth anniversary of the republic, referred to this day as... the biggest holiday He described it as such.

https://tr.wikipedia.org/wiki/29_Ekim_Cumhuriyet_Bayram%C4%B1