Schools and many offices often close for a full or half day on major Turkish holidays, which are as follows: January 1 (New Year's Day); April 23 (National Independence Day); May 1 (Labor and Solidarity Day); May 19 (Atatürk's Commemoration Day, celebrating his birthday and the day he landed in Samsun, starting the independence movement); August 30 (Zafer Bayramı, or Victory Day, commemorating the final Turkish victory over Greek forces in 1922, during Turkey's War of Independence); and October 29 (Cumhuriyet Bayramı, or Republic Day, celebrating Atatürk's proclamation of the Turkish republic in 1923—many businesses and government offices also close at midday, usually either 12:30 or 1, on the day before Republic Day). November 10, the anniversary of Atatürk's death, is not a full-day public holiday but is commemorated by a nationwide moment of silence at 9:05 am. Many provincial towns also hold celebrations to mark the anniversary of the date that the Greeks were driven out of the area during the Turkish War of Independence.
Turks also celebrate the two main Muslim religious holidays each year: the three-day Şeker Bayramı, marking the end of Ramadan (called "Ramazan" in Turkey) and the four-day Kurban Bayramı, which honors the prophet Ibrahim’s (Abraham in the Old Testament) willingness to sacrifice his son to God. Because the Muslim year is based on the lunar calendar, the dates of the two holidays change every year, both moving earlier by 11 to 12 days each year. The precise timing may vary slightly according to the sighting of the moon. Many businesses and government offices close at midday, usually either 12:30 or 1 pm, on the day before the religious bayrams. In 2016, Şeker Bayramı is due to begin at midday on July 4 and last until the evening of July 7; in 2017 it will begin on June 25 and end on the 27th. Kurban Bayramı will begin at midday on September 11, 2016, and continue through the evening of September 15; in 2017 it will begin on August 31 and end on September 4th. A word of note: if a religious holiday takes up three or four days of a working week, the government will often declare the rest of the week an official holiday as well. However, such decisions are usually made less than a month before the holiday actually begins.