1. King Kalakaua's Birthday: November 21 marks the birthday of Hawaii's last reigning monarch, King David Kalakaua. Born in 1836, he ruled the Kingdom of Hawaii from 1874 until his death in 1891 and was known as the "Merry Monarch" for his fondness for social gatherings and music.

2. The Matson Navigation Company: On November 21, 1882, William Matson founded the Matson Navigation Company, which played a key role in the development of Hawaii's tourism industry by providing regular passenger and freight service between California and the Hawaiian Islands.

3. The Attack on Pearl Harbor: On November 21, 1941, the Japanese aircraft carrier task force that would later attack Pearl Harbor departed from Hitokappu Bay on the island of Etorofu in the Kuril Islands. The surprise attack on December 7, 1941, would lead to the United States' entry into World War II.

4. Hawaiian Statehood: On November 21, 1959, President Dwight D. Eisenhower signed a proclamation admitting Hawaii as the 50th state of the United States. The admission followed a long struggle for statehood by Hawaii's residents and marked the end of a century-long period of U.S. colonization of the islands.

5. Cane Fires: November 21 is the start of the annual sugarcane harvesting season in Hawaii, which runs from November to early April. During this time, residents of the state often see large clouds of smoke as fields of sugarcane are burned to make harvesting easier. While controversial, this tradition has been a part of Hawaii's agriculture industry for over a century.