National Batik Day is Indonesia’s national celebration day to commemorate the designation of batik as a Humanitarian Heritage for Oral and Intangible Culture (Masterpieces of the Oral and Intangible Heritage of Humanity) on 2 October 2009 by UNESCO.
The selection of National Batik Day on October 2 is based on the decision of UNESCO, the UN agency in charge of Education, Science and Culture, which officially recognizes Indonesian batik as world cultural heritage. UNESCO includes batik in the Representative List of Intangible Cultural Heritage of Humanity. Recognition of batik is international recognition of Indonesian culture.
Source : https://id.wikipedia.org/wiki/Hari_Batik_Nasional