National Batik Day (Hari Batik Nasional) is observed in Indonesia every October 2. This holiday commemorates the anniversary of Indonesian batik being designated as a Masterpiece of Oral and Intangible Heritage of Humanity by UNESCO in 2009. Batik is a traditional technique of wax-resist dyeing applied to cloth, allowing artisans to create intricate patterns, many of which hold symbolic meanings, such as bringing good luck or health. On this day, it is customary for Indonesian people, particularly government officials, employees of state-owned enterprises, and students, to wear batik attire to celebrate their cultural heritage. The day serves as a recognition of the importance of batik in Indonesian culture and encourages the appreciation of this unique art form.