The Vietnamese Calendar holiday recurrence rule type is for holidays based on either the Vietnamese lunar calendar or the Vietnamese solar calendar, and its holidays follow the same structure as holidays based on the Chinese calendar.
The structure of Vietnamese lunar calendar holidays is a month-day pair.
Gio to Hung Vuong (Vietnam)
Contrary to Chinese holidays which are sometimes based on the Chinese solar calendar, at the time of writing this topic (June 2021), all Vietnamese public holidays are based on the Vietnamese lunar calendar.
Topic 179090, last updated on 14-Apr-2020