Lunar and solar calendars Vietnam

Calendars in Vietnam, origins and influences

Before explaining the specificities of the Vietnamese Lunar and Solar Calendars, it is useful to remind you of their origin and usage all over the world.

Calendars and zodiac signs have influenced all civilizations throughout time. Around the world, many calendars are used to measure time, but the main ones are the solar calendar, the lunar calendar, and the lunisolar calendar.

The solar calendar is based only on the annual cycle of the Sun; the lunar calendar on the phases of the Moon; the lunisolar calendar is based on both the annual cycle of the Sun and the phases of the Moon. The Sun and the Moon are the two stars that contribute to the construction of the majority of the calendars.

In this article, Horizon Vietnam Travel offers you a general overview of the 3 types of calendars and also on the corresponding zodiac signs. Let’s explore them!

How is a solar year formed?

One movement of the Earth around the Sun takes 365.2422 days (365 days 5 hours 48 minutes 46 seconds). To facilitate the calculation, we take 365 days for a solar year. In these 365 days, we see a total of 12 times the full moon, so a year is divided into 12 months. Due to the fact that 365 is not divisible by 12, a year must be divided into complete months (31 days) and incomplete months (30 days). February is also an incomplete month, but it only has 28 days.

And 5 hours 48 minutes and 46 seconds left? For 4 consecutive years, this balance forms almost a day, and this day is added in February of the fourth year. This fourth year is called a “leap year”, with 366 days. The month of February of the leap year has 29 days, the 29th day of this month is called “leap day”.

And a lunar year?

The moon is important for measuring time. The lunar year is calculated based on the full moon phase. The full moon is the phenomenon during which this star appears to us the brightest. The ancients discovered that the full moon phase lasts 29.53 days. They took this phase as a way to calculate time and called it “months”, including complete and incomplete months.

A year has 12 full moons, so the ancients divided it into 12 months. A lunar year has 354 or 355 days. A complete month has 30 days, while an incomplete month has 29 days.

The Chinese calendar is often confused with the lunar calendar. In fact, the calendar used by the Chinese is a lunisolar calendar. The lunar calendar is officially used by the Islamists, they only use this type of calendar – based on a year of 12 lunar months of 29 to 30 days each.

About the lunisolar calendar

The weather changes due to the fact that the Earth itself revolves around an axis inclined at 23 degrees and around the sun. We speak of full seasons to characterize summer and winter, and of mid-seasons to qualify spring and autumn. A period of changes from warm weather to cold weather is 364 days. A lunar year has only 354 – 355 days, so every year a gap of 10-11 days widens between the solar calendar and the lunar calendar.

After 3 years, the gap is more than a month. So after three consecutive years, according to the climate change cycle, the elders would add a month to the third year. This year would have 13 months (384 or 385 days), the added month is called “leap month”. The method of using a leap month to adapt to the climate change cycle is actually a combination of the lunar calendar and the solar calendar. Such a calendar is called a lunisolar calendar.

The lunisolar calendar is also called the traditional Chinese calendar. This type of calendar is widely used to define traditional holidays. Another purpose is to help choose a lucky day for important events such as marriage, moving to a new house, etc.

Calendars in Vietnam

Two types of calendars are applied in Vietnam: solar calendar and lunisolar calendar in Vietnam. The solar calendar is used for international holidays, the other – the lunisolar calendar is used for traditional holidays and rituals such as marriage, ancestor worship, etc.

Tet Festival or Vietnamese Lunar New Year (better to say: Vietnamese Lunar-Solar New Year) is the most important holiday in Vietnam. Due to the calculation made by the lunisolar calendar, Tet often occurs at the end of January, which is later than New Year’s Day. Tet is a pleasant time for foreign tourists to spend their holidays in Vietnam enjoying the festive atmosphere. For example, the Tet holiday 2020 fell on January 25, 2020.

Important holiday dates in Vietnam

Besides Tet, there are other important holidays in Vietnam:

• Hung Kings worship ceremony (10/3 – lunisolar calendar): the worship of the Hùng Kings is a strong expression of the awareness of the national history and the respect of the common people towards their ancestors.
• Buddha’s birthday (15/4 – lunisolar calendar): Buddha’s birthday festival is not only a religious festival but also a national festival.
• Reunification Day (30/4): the victory of the Vietnamese People’s Army over the American armed forces by taking Saigon.
• Birthday of President Ho Chi Minh (19/5): President Ho Chi Minh is a symbol of national spirit who dedicated his life to the liberation of the Vietnamese people (19/5/1890 – 2/9/1969).
• National Day (2/9): Vietnam’s National Day commemorates the proclamation of Vietnam’s independence by Ho Chi Minh on September 2, 1945.
• August Revolution Day (19/8): the success of the August Revolution gave birth to the state of the Democratic Republic of Vietnam.
• Vu Lan Festival (15/7 – lunisolar calendar): literally “absolution of the dead” – a great Buddhist festival.
• Mid-Autumn Festival (15/8 – lunisolar calendar): during this festival of the end of the harvest, Vietnamese usually eat glutinous rice cakes in the shape of the moon, filled with lotus seeds, watermelon, peanut, duck egg yolk, grapes, and sugar.
• Household genie festival (23/12 – lunar calendar): the family’s tutelary genie will leave for Heaven on the night of the 23rd day of the last lunar month on a carp to report the family for one year to the Jade Emperor. On this day, the house is cleaned, especially the kitchen and a tray of offerings are prepared to say goodbye to the genie.

12 zodiac signs and uses in Vietnamese calendars

Chinese astrology is based on a 12-year cycle. The cycle is based on the traditional Chinese calendar and each year corresponds to an animal. The twelve animals of the Chinese zodiac are, in order: the rat, the ox, the tiger, the rabbit, the dragon, the snake, the horse, the goat, the monkey, the rooster, the dog and the pig.

According to a legend, at the time of leaving the earth, the Buddha invited all his friends and animals to come and say goodbye. Among the animal friends, there were only 12 who responded to the Buddha’s invitation. To thank them, the Buddha decided to bear the names of the 12 animals that came to bid him farewell in each year of the lunisolar cycle.

In this part, Horizon Vietnam Travel explains how to know your astrological sign. Discover everything about your lucky animal!

Table of correspondence

Horizon Vietnam Travel hopes that this article will be useful to you with the information provided on the calendars in Vietnam and the zodiac signs. Have a good reading!