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Thai solar calendar

Thai solar calendar is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Thai solar calendar rather than just read about it. In short: The Thai solar calendar (Thai: ปฏิทินสุริยคติไทย, RTGS: patithin suriyakhati thai, "Thai solar calendar") was adopted by King Chulalongkorn (Rama V) in 1888 CE as the Siamese version of the Gregorian calendar, replacing the Thai lunar calendar as the legal Thai calendar (though the latter is still also used, especially for traditional and religious events). Years are now counted in the Buddhist Era (B.E.): พุทธศักรา…

Thai solar calendar — main illustration
Thai solar calendar — illustration

Key takeaways

  • Thai solar calendar belongs to astronomy; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Thai solar calendar to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Thai solar calendar from memory before moving on to harder problems.

Reference excerpt

The Thai solar calendar (Thai: ปฏิทินสุริยคติไทย, RTGS: patithin suriyakhati thai, "Thai solar calendar") was adopted by King Chulalongkorn (Rama V) in 1888 CE as the Siamese version of the Gregorian calendar, replacing the Thai lunar calendar as the legal Thai calendar (though the latter is still also used, especially for traditional and religious events). Years are now counted in the Buddhist Era (B.E.): พุทธศักราช, พ.ศ. RTGS: Phutthasakkarat (lit. 'era of the Shaka Buddha') which is 543 years ahead of the Gregorian calendar.

Years

The Siamese generally used two calendars, a sacred and a popular (vulgar in the classical sense). The vulgar or minor era (จุลศักราช, chula sakarat) was thought to have been instituted with the introduction of Buddhism, and corresponds to the traditional Burmese calendar (abbreviated ME or BE, the latter not to be confused with the abbreviation for the Buddhist Era, which is the sacred era.)

Rattanakosin Era

King Chulalongkorn (Rama V) decreed a change in vulgar reckoning to the Rattanakosin Era (รัตนโกสินทรศก, Rattanakosin Sok abbreviated ร.ศ. and R.E.) in 1889 CE. The epoch (reference date) for Year 1 was 6 April 1782 with the accession of Rama I, the foundation of the Chakri dynasty, and the founding of Bangkok as the capital of Rattanakosin Kingdom. To convert years in R.E. to the Common Era, add 1781 for dates from 6 April to December, and 1782 for dates from January to 5 April.

Buddhist Era

In Thailand the sacred, or Buddhist Era, is reckoned to have an epochal year 0 from 11 March 543 BC, believed to be the date of the death of Gautama Buddha. King Vajiravudh (Rama VI) changed year counting to this Buddhist Era (abbreviated BE) and moved the start of the year back to 1 April in 2455 BE, 1912 CE. This change marked the end of the Rattanakosin Era as the official calendar, and the Buddhist Era became the primary calendar system for the Thai government. To convert years in B.E. to the Common Era, subtract 543.

New year New Year, the time at which a new calendar year begins and the calendar's year count is incremented, originally coincided with the date calculated for Songkran, when the Sun transits the constellation of Aries, the first astrological sign in the Zodiac as reckoned by sidereal astrology: thus the year commenced on 11 April 1822. As previously noted, Rama VI moved the start of the year back to 1 April in 2455 BE, 1912 CE, so that 130 R.S. only lasted for 356 days from 11 April 1911 to 31 March 1912. On 6 September 1940, Prime Minister Phibunsongkhram decreed 1 January 1941 as the start of the year 2484 BE, so year 2483 BE had only nine months running from 1 April to 31 December 1940. To convert dates from 1 January to 31 March prior to that year, the number to add or subtract is 542; otherwise, it is 543. Example:

Today, both the Common Era New Year's Day (1 January) and the traditional Thai New Year (สงกรานต์, Songkran) celebrations (13–15 April) are public holidays in Thailand. In the traditional Thai calendar, the change to the next Chinese zodiacal animal occurs at Songkran (now fixed at 13 April.) For Thai Chinese communities in Thailand, however, the Chinese calendar determines the day that a Chinese New Year begins, and assumes the name of the next animal in the twelve-year animal cycle.

Months Names of the months derive from Hindu astrology names for the signs of the zodiac. Thirty-day-month names end in -ayon (-ายน), from Sanskrit root āyana, meaning the arrival of; 31-day-month names end in -akhom (-าคม), from Sanskrit āgama (cognate to English "come") that also means the arrival of. February's name ends in -aphan (-าพันธ์), from Sanskrit bandha, meaning "fettered" or "bound". The day added to February in a solar leap year is Athikasurathin (อธิกสุรทิน, respelled to aid pronunciation (อะทิกะสุระทิน) from Sanskrit adhika: "additional"; and sura: "move".

Days

Problems Using Buddhist era could easily cause confusion between itself and Anno Domini in the historical context. For example, Anno Domini 2026, and Buddhist year 2026 (which corresponds to AD 1483). Two-digit year numbering could cause even more confusion. Another problem is the counting of the Buddhist era, which has changed several times in the past, including the inclusion of year 0, and the change of New Year's Day from April to January in 1941, has caused confusion in historical context as well. For example, many Thai people regard the establishment of the Ayutthaya Kingdom to be in 1350, which is direct conversion from Buddhist era 1893, while the actual date is 1351. In computer programming, using the Buddhist era has sometimes caused the computer programs to void the license immediately, as the input values of the Buddhist era would exceed the expiration date for the program. Some users report that dates appear in future dates, due to the input data being the Buddhist era, while the computer is designed to accept Anno Domini.

See also

Buddhist calendar Date and time notation in Thailand Public holidays in Thailand Thai 6-hour clock Thai lunar calendar Time in Thailand

References

Eade, John Christopher. 1995. The Calendrical Systems of Mainland South-East Asia. Handbuch der Orientalistik: Dritte Abteilung, Südostasien 9. Leiden and New York: E. J. Brill. ISBN 90-04-10437-2 na Nakorn, Bleung (comp.). [1971]. นายเปลื้อง ณ นคร ผู้รวบรวม ปทานุกรมนักเรียน ไทยวัฒนาพานิช กทม. Student's Handbook. Bangkok: Thai Wattana Panit, 2514. Sethaputra, So. 1999. New Model English – Thai Dictionary. [Krung Thep Maha Nakhon?: Thai Watthana Phanit?]. ISBN 974-08-3253-9 Thai calendar for August 2004. Web dictionary Thai-English English-Thai

External links Thai Time by Anthony Diller Archived 25 March 2015 at the Wayback Machine Thai Buddha Images for the Days of the Week Thai Lunar/Solar Calendar (BE.2300–2584) (Thai Language)

Illustrations

Thai solar calendar: A panel from a typical calendar, showing the month of August 2004 (B.E. 2547). Lunar dates are also provided.
A panel from a typical calendar, showing the month of August 2004 (B.E. 2547). Lunar dates are also provided.

Worked examples

Example 1 — a first encounter with Thai solar calendar

Start with the simplest possible case. Write down what Thai solar calendar claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Thai solar calendar before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Thai solar calendar ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Thai solar calendar

In research
Thai solar calendar appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Thai solar calendar in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Thai solar calendar is common in secondary-school and first-year university syllabi. It links to neighbouring topics Culture of Thailand, Modified Gregorian calendars, Solar calendars, so understanding it makes those chapters shorter.
In everyday life
Look for Thai solar calendar outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Thai solar calendar in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Thai solar calendar means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Thai solar calendar out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Thai solar calendar in simple terms?

The Thai solar calendar (Thai: ปฏิทินสุริยคติไทย, RTGS: patithin suriyakhati thai, "Thai solar calendar") was adopted by King Chulalongkorn (Rama V) in 1888 CE as the Siamese version of the Gregorian calendar, replacing the Thai lunar calendar as the legal Thai calendar (though the latter is still…

Why does Thai solar calendar matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Thai solar calendar?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Thai solar calendar.

Tags

  • Culture of Thailand
  • Modified Gregorian calendars
  • Solar calendars
  • Specific calendars
  • Time in Thailand

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