Tet absorbs most of the attention, and reasonably so, but Vietnam's year has a dozen other dates worth knowing. Some are worth planning a trip around. Two of them will close things and fill beaches whether you planned for them or not.
The two that affect your logistics
Reunification Day on 30 April and International Labour Day on 1 May fall together and function as a long domestic holiday. Vietnamese travellers fill coastal resorts, Da Lat and Sapa, prices rise sharply, and domestic flights and hotels book out. The exact length of the break is set by government announcement each year because it depends on how the dates land against the weekend, so check it rather than assuming a fixed span.
National Day on 2 September is the other one, and it follows the same pattern: domestic travel surges and the beaches fill. Its length also depends on how the date falls against the weekend, so check the year rather than assuming it is the shorter of the two. Hanoi holds official ceremonies around Ba Dinh Square, which is worth seeing but closes roads.
Why these matter more than the cultural dates
Festivals mostly add something to a trip. Public holidays subtract capacity from it. If you are choosing between two weeks and the only difference is that one contains a national holiday, that is a real reason to pick the other.
The lunar dates worth planning around
Most Vietnamese festivals follow the lunar calendar, so their Gregorian dates shift each year and need checking for your own travel year.
The Perfume Pagoda festival runs from shortly after Tet through to around the third lunar month, drawing very large crowds to the boat-and-cave pilgrimage southwest of Hanoi. Going outside the festival means a calm trip; going during it means seeing something genuinely communal, with the crowds that implies.
Hung Kings Temple Festival, on the tenth day of the third lunar month, is a public holiday honouring Vietnam's legendary founders, centred on Phu Tho province north of Hanoi. It adds a day off to the domestic calendar.
Mid-Autumn Festival, on the fifteenth day of the eighth lunar month, usually September, is the one most visitors enjoy most. Lanterns, mooncakes, lion dances and children in the streets. Hoi An is spectacular for it, and Hanoi's Old Quarter fills with lantern sellers in the run-up.
Hoi An's monthly lantern night
Separately from any festival, Hoi An turns off its electric lights on the fourteenth day of each lunar month and lights the old town with lanterns. It happens every month, it is beautiful, and it is easy to catch by accident or to plan for with a calendar check.
Regional and seasonal events
Hue hosts a biennial festival of royal arts and performance in its citadel, typically in spring, which transforms the city when it runs. Da Nang's international fireworks competition brings weekend displays over the Han River across several months in summer, and fills hotels on those weekends.
In the far north, the ethnic-minority markets have their own rhythm — Bac Ha's Sunday market being the best known and the most worth building a Sapa itinerary around, since it only happens on Sundays. Harvest in the northern terraces falls around September and October and is the reason those months are the photographic peak for Sapa and Ha Giang.
