National Santri Day is observed in Indonesia every October 22 to honor the santri, one of the two groups of Javanese Muslims identified by anthropologist Clifford Geertz. This day commemorates the role of the santri in the Indonesian independence movement, particularly their declaration of a holy war against Dutch colonial forces after the country's independence was proclaimed. The santri adhere to a more orthodox version of Islam, engaging in practices such as reading the Qur'an and following Sharia law, in contrast to the abangan, who incorporate various cultural elements into their faith. The observance was established by the Indonesian government in 2015 to mark the anniversary of the founding of Nahdlatul Ulama, a significant traditionalist Sunni Islamic organization that emerged from the santri community in 1926. Today, Nahdlatul Ulama is recognized as the world's largest independent Islamic organization, contributing to education and poverty alleviation in Indonesia.