But really outside of the official festivities taking place in the capital city that the rest of the island watches on the news, I've never seen much ado made of this holiday.
So, what is Double Ten Day you ask . . . it is "National Celebration Day." Many also call it the birthday of Taiwan. In fact, I saw on the news this morning the mayor of Taipei singing "happy birthday" and cutting a cake covered in Taiwan flags.
According to Wikipedia: Double Ten Day is the national day of the Republic of China and celebrates the start of the Wuchang Uprising of October 10, 1911, which led to the collapse of the Qing Dynasty.