The Vietnamese calendar (Vietnamese : âm lịch/陰曆) is a lunisolar calendar that is mostly based on the lunisolar Chinese calendar. As Vietnam's official calendar has been the Gregorian calendar since 1954, the Vietnamese calendar is used mainly to observe lunisolar holidays and commemorations, such as Tết and Mid-Autumn Festival.
After Vietnam regained independence following the third Chinese dominion of Viet-Nam, monarchs established their own calendars based on Chinese prototypes, and every subsequent dynasty had appointed officers to man and create the calendar to be used in the realm. :授時; pinyin :shòu shí) calendar to the Vietnamese Trần dynasty.According to the Đại Việt sử lược historical chronicles, the Vietnamese rulers started building astronomical/astrological facilities in the capital Thăng Long Chữ Hán: 昇龍 (i.e. modern Hanoi) as early as 1029. Beginning in 1324, the Chinese Yuan dynasty introduced the Thụ Thời (Chinese
|Calendar name||Year in use||Notes|
|Thụ Thời (Chinese :授時; pinyin :shòu shí)||1324–1339||Introduced by the Chinese Yuan dynasty to the Vietnamese Trần dynasty.|
|Hiệp Kỷ (Chữ Hán: 協紀)||1339–1401||Probably a name change with no changes to calculation methods.|
|Thuận Thiên (Chữ Hán: 順天)||1401–1413||Hiệp Kỷ calendar abolished, with Thuận Thiên replacing it. There was no documentation on the difference between the two.|
|Đại Thống (Chinese :大統; pinyin :dà tǒng)||1413–1813||Introduced by the Chinese Ming dynasty in 1369, during the Fourth Chinese domination of Vietnam, the Ming administration in Vietnam used the Datong calendar. At the start of the Vietnamese Lê dynasty in 1428, the end of Chinese domination over Vietnam, there was no evidence that the calendar was changed.|
|Hiệp Kỷ (Chữ Hán: 協紀) —Shíxiàn (Chinese :時憲; pinyin :shí xiàn)||1813–1840||Hiệp Kỷ is not to be confused with its earlier namesake. It was essentially the Shíxiàn calendar introduced by the Chinese Qing dynasty to the Vietnamese Nguyễn dynasty.|
|Gregorian||early 19th century||The Gregorian calendar was introduced by the French, and was used in Vietnamese administrative offices at the same time as the Hiệp-kỷ calendar, which remained in use by the Vietnamese royal court.|
|Hiệp Kỷ (Chữ Hán: 協紀)||1841–1954||Beginning in 1841, Hiệp Kỷ began to differ from Shíxiàn due to longitudinal differences between Vietnam and China.|
Beginning in 1954, Vietnamese administrative offices officially used the Gregorian calendar, while the civilian populace continued to use a variety of local calendars derived from French, Chinese and Japanese sources, including the Hiệp Kỷ calendar.On 8 August 1967, the North Vietnamese government issued a decree to change Vietnamese standard time from UTC+8 to UTC+7, as well as make the Gregorian calendar the sole official calendar, restricting lunisolar calendar use to holidays and commemorations. South Vietnam would later join this change at the end of the Vietnam War in 1975.
The Chinese calendar is based on astronomical observations and is therefore dependent on what is considered the local standard time. North Vietnam switched from UTC+8 to UTC+7 on 8 August 1967, with South Vietnam doing likewise in 1975 at the end of the Vietnam War. As a result of the shift, North and South Vietnam celebrated Tết 1968 on different days.This effect would see the solstice falling on 21 December in Hanoi, while it was 22 December for Beijing.
As the 11th month of the Chinese calendar must contain the winter solstice, it is not the month from 23 November 1984 to 21 December 1984 as per the Vietnamese calendar, but rather the one from 22 December 1984 to 20 January 1985. The effect of this is that the Vietnamese New Year would fall on 21 January 1985, whereas the Chinese New Year would fall on 20 February 1985, a one-month difference. The two calendars agreed again after a leap month lasting from 21 March to 19 April of that year was inserted into the Vietnamese calendar.
In the Vietnamese zodiac, the cat replaces the Rabbit in the Chinese zodiac. So, a child born in the Chinese year of the Rabbit will be born in the Vietnamese year of the Cat (mẹo/mão). The Vietnamese zodiac uses the same animals as the Chinese zodiac for the remaining 11 years, though the Ox of the Chinese zodiac is usually considered to be a water buffalo (sửu/trâu) in the Vietnamese zodiac.
The traditional Chinese calendar, is a lunisolar calendar which identifies years, months, and days according to astronomical phenomena. In China, it is defined by the Chinese national standard GB/T 33661–2017, "Calculation and Promulgation of the Chinese Calendar", issued by the Standardization Administration of China on May 12, 2017.
A lunar calendar is a calendar based on the monthly cycles of the Moon's phases, in contrast to solar calendars, whose annual cycles are based only directly on the solar year. The most commonly used calendar, the Gregorian calendar, is a solar calendar system that originally evolved out of a lunar calendar system. A purely lunar calendar is also distinguished from a lunisolar calendar, whose lunar months are brought into alignment with the solar year through some process of intercalation. The details of when months begin varies from calendar to calendar, with some using new, full, or crescent moons and others employing detailed calculations.
A lunisolar calendar is a calendar in many cultures, combining lunar calendars and solar calendars. The date of Lunisolar calendars therefore indicates both the Moon phase and the time of the solar year, that is the position of the Sun in the Earth's sky. If the sidereal year is used instead of the solar year, then the calendar will predict the constellation near which the full moon may occur. As with all calendars which divide the year into months there is an additional requirement that the year have a whole number of months. In this case ordinary years consist of twelve months but every second or third year is an embolismic year, which adds a thirteenth intercalary, embolismic, or leap month.
A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by reference to the solstices and the equinoxes.
Tết, short for Tết Nguyên Đán, Spring Festival,Lunar New Year, orVietnamese Lunar New Year is one of the most important celebrations in Vietnamese culture. The colloquial term "Tết" is a shortened form of Tết Nguyên Đán, with Old Vietnamese origins meaning "Festival of the First Morning of the First Day". Tết celebrates the arrival of spring based on the Vietnamese calendar, which usually has the date falling in January or February in the Gregorian calendar.
Chinese astrology is based on the traditional astronomy and calendars. Chinese astrology came to flourish during the Han Dynasty.
New Year's Day is a festival observed in most of the world on 1 January, the first day of the year in the modern Gregorian calendar. 1 January is also New Year's Day on the Julian calendar, but this is not the same day as the Gregorian one. Whilst most solar calendars begin the year regularly at or near the northern winter solstice, cultures that observe a lunisolar or lunar calendar celebrate their New Year's Day at less fixed points relative to the solar year.
The Ox is the second of the 12-year periodic sequence (cycle) of animals which appear in the Chinese zodiac related to the Chinese calendar, and also appears in related calendar systems. The Chinese term translated here as ox is in Chinese niú , a word generally referring to cows, bulls, or neutered types of the bovine family, such as common cattle or water buffalo. The zodiacal ox may be construed as male, female, neutered, hermaphroditic, and either singular or plural. The Year of the Ox is also denoted by the Earthly Branch symbol chǒu. The term "zodiac" ultimately derives from an Ancient Greek term referring to a "circle of little animals". There are also a yearly month of the ox and a daily hour of the ox. Years of the oxen (cows) are cyclically differentiated by correlation to the Heavenly Stems cycle, resulting in a repeating cycle of five years of the ox/cow, each ox/cow year also being associated with one of the Chinese wǔxíng, also known as the "five elements", or "phases": the "Five Phases" being Fire, Water, Wood, Metal, and Earth. The Year of the Ox follows after the Year of the Rat which happened in 2020 and it then is followed by the Year of the Tiger, which will happen in 2022.
Lunar New Year is the beginning of a calendar year whose months are Moon cycles, based on the lunar calendar or lunisolar calendar. It is particularly celebrated in countries within East and Southeast Asia (ESEA), being influenced by the Chinese lunisolar calendar. It is also a feature of the Hinduism –Buddhist calendars of South Asia, as well as the Islamic and Jewish calendars.
The Mid-Autumn Festival, also known as the Moon Festival or Mooncake Festival, is a traditional festival celebrated in mainland China, Taiwan, Hong Kong, Macau, and Vietnam, as well as by overseas Chinese and Vietnamese communities. Similar holidays are celebrated in Japan, Korea, and throughout Southeast Asia.
The traditional Korean calendar or Dangun calendar is a lunisolar calendar. Like most traditional calendars of other East Asian countries, the Korean Calendar is mainly derived from the Chinese calendar. Dates are calculated from Korea's meridian, and observances and festivals are based in Korean culture.
The sexagenary cycle, also known as the Stems-and-Branches or ganzhi, is a cycle of sixty terms, each corresponding to one year, thus a total of sixty years for one cycle, historically used for recording time in China and the rest of the East Asian cultural sphere. It appears as a means of recording days in the first Chinese written texts, the Shang oracle bones of the late second millennium BC. Its use to record years began around the middle of the 3rd century BC. The cycle and its variations have been an important part of the traditional calendrical systems in Chinese-influenced Asian states and territories, particularly those of Japan, Korea, and Vietnam, with the old Chinese system still in use in Taiwan, and to a lesser extent, in Mainland China.
In Western astrology, astrological signs are the twelve 30 degree sectors that make up Earth's 360 degree orbit around the Sun. The signs enumerate from the first day of spring known as the First Point of Aries which is the vernal equinox. The Western astrological signs are Aries, Taurus, Gemini, Cancer, Leo, Virgo, Libra, Scorpio, Sagittarius, Capricorn, Aquarius and Pisces. The Western zodiac originated in Babylonian astrology, and was later influenced by Hellenistic culture. Each sign was named after a constellation the sun annually moved through while crossing the sky. This observation is emphasized in the simplified and popular sun sign astrology. Over the centuries, Western astrology's zodiacal divisions have shifted out of alignment with the constellations they were named after by axial precession while Hindu astrology measurements correct for shifting.Astrology has developed in Chinese and Tibetan cultures as well.
The Buddhist calendar is a set of lunisolar calendars primarily used in mainly South and Southeast Asian countries such as Cambodia, Laos, Sri Lanka, Myanmar and Thailand as well as in Chinese populations of Malaysia, Singapore and Vietnam for religious or official occasions. While the calendars share a common lineage, they also have minor but important variations such as intercalation schedules, month names and numbering, use of cycles, etc. In Thailand, the name Buddhist Era is a year numbering system shared by the traditional Thai lunisolar calendar and by the Thai solar calendar.
A solar term is any of twenty-four periods in traditional Chinese lunisolar calendars that matches a particular astronomical event or signifies some natural phenomenon. The points are spaced 15° apart along the ecliptic and are used by lunisolar calendars to stay synchronized with the seasons, which is crucial for agrarian societies. The solar terms are also used to calculate intercalary months; which month is repeated depends on the position of the sun at the time.
The September equinox is the moment when the Sun appears to cross the celestial equator, heading southward. Due to differences between the calendar year and the tropical year, the September equinox may occur anytime from September 21 to 24.
In Thailand, two main calendar systems are used alongside each other: the Thai solar calendar, based on the Gregorian calendar and is used for official and most day-to-day purposes, and the Thai lunar calendar, used for traditional events and Buddhist religious practices.
Korean New Year is a festival and national holiday commemorating the first day of the Korean calendar. It is one of the most important traditional Korean holidays. The celebration usually lasts three days: the day before Korean New Year, Korean New Year itself, and the day after Korean New Year. During this time, many Koreans visit family, perform ancestral rites, wear hanbok (한복), eat traditional food, and play folk games. Additionally, children often receive money from their elders after performing a formal bow.
The Chinese zodiac is a traditional classification scheme based on the lunar calendar that assigns an animal and its reputed attributes to each year in a repeating twelve-year cycle. Originating from China, the zodiac and its variations remain popular in many East Asian and Southeast Asian countries, such as Japan, South Korea, Taiwan, Vietnam, Cambodia, Singapore, Nepal, Bhutan and Thailand.