Korea
Hangul Day (also spelled as Hangeul Day) is a day that celebrates the creation of the Hunminjeongeum (Hangul, Korean alphabet), which was inscribed to the UNESCO Memory of the World Register in 1997. Hangul was created by Sejong the Great in 1443 and proclaimed in 1446. Before the creation of Hangul, people in Korea (known as Joseon at the time) primarily wrote using Classical Chinese alongside native phonetic writing systems that predate Hangul by hundreds of years, including idu, hyangchal, gugyeol, and gakpil. However, due to the fundamental differences between the Korean and Chinese languages, and the large number of characters needed to be learned, there was much difficulty in learning how to write using Chinese characters for the lower classes, who often didn't have the privilege of education. To assuage this problem, King Sejong created the unique alphabet known as Hangul to promote literacy among the common people. Hangul Day was founded in 1926 during the Japanese occupation by members of the Korean Language Society, whose goal was to preserve the Korean language during a time of rapid forced Japanization. Today, both South Korea and North Korea celebrate Hangul Day as a national holiday.Sources
Korean mixed script
In 1446, King Sejong the Great (朝鮮 世宗大王, 조선 세종대왕) introduced "hunminjeong-eum" (訓民正音, 훈민정음), 'correct pronunciation for teaching the people' in a proclamation, published with extensive description of the new alphabet. Sejong begins the document (in literary Chinese), 'Because our language is different from the Chinese language, our poor people cannot express themselves in Chinese writing. In my pity for them I create twenty-eight letters, which all can learn easily and use in their daily lives.' This script is now known as "hangul" in South Korea and "choseongul" in North Korea, with the proclamation celebrated as national holidays on the 9th of October in the south and the 15th of January in the north, respectively.
The new script spread rapidly among the segments of society that were traditionally denied access to education, such as women (except those in the higher classes), farmers, fishermen, rural merchants and children. Despite later attempts to ban the Korean alphabet, as commoners wrote disparaging this about rulers they disliked, and the fear that the upper classes would lose the privileges of being literate in Chinese led to attempts to ban the alphabet, but "hangul" survived. The twenty-eight letters, arranged into syllable blocks, actually facilitated the study of "hanja" as they were used in teaching guides to indicate the native word and the Sino-Korean pronunciation, and the upper class, despite their disdain, would often have to study the "gugyeol" system of knowing a Chinese character's meaning, Sino-Korean pronunciation and its native Korean equivalent, and "hangul" thus became an important tool in teaching "hanja". Nevertheless, its use as an exclusive writing system was mocked by the upper classess as "jinseo" (真書, 진서) or 'real script.'