Faculty of Asian Studies


Thai Time

Anthony Diller, Preecha Juntanamalaga
Australian National University, 2000

[A revised version of the Keynote Speech presented before Her Royal Highness Princess Galayani Vadhna on the occasion of her presiding over the International Conference on Tai Languages and Cultures, Thammasat University, 7-8 December 1995. The Australian Research Council has supported the work reported here, conducted in cooperation with Professor Dr B.J. Terwiel and Dr J.C. Eade. What follows is especially indebted to analyses in Thai of Professor Prasert Na Nagara. The Bibliography should be consulted for further detail on the work of these and other colleagues.]


Readers may still remember just where and how they celebrated the progression of the calendar to the year 2000. This calendrical milestone in Western cultures, widely celebrated with revelry, pyrotechnic displays and general enthusiasm, marks an interesting contrast to a similar calendrical event in the traditional Thai milieu. Over three hundred years ago, on the approach of the year 1000 in the Thai reckoning system then official (the ‘Chulasakarat era’) King Prasat Thong and his kingdom did not prepare for celebrations. According to the traditional account, the king was so concerned that disasters and calamities would accompany the millennial progression that he went so far as to decree a change in the royal calendar to avoid them. This is just one piece of evidence suggesting that contrasting sensibilities regarding units of time, as well as the units of time themselves, need to be seen as part of how cultures differ.

Another difference. The Western year 2000 also marks the Year of the Dragon in the 12-year animal sequence widely used in East and Southeast Asia. Birthdays that are multiples of 12 are especially important to Thai people, as to other East Asian peoples, as the cycle brings them back to their birth-year animal. The present King of Thailand was born in a Rabbit year, so his sixth cycle was celebrated in 1999, with great festivity. Traditional Thai beliefs also relate your animal year to how well you get along with other people.

The year 2000 is not so significant for the Thai people as a major turning point; it is rather celebrated as the Golden Wedding anniversary of the present King and Queen of Thailand, illustrating again linkages between court and calendar in the Thai context. 2000 in the Western calendar (AD, or as some prefer, CE) is equivalent to 2543 in the Buddhist-era calendar (‘phutthasakarat era’, usually abbreviated BE) officially used in Thailand since 1912 AD. This reckoning starts from the Buddha’s demise or passing to Nirvana, 543 years before the advent of the Christian era. Therefore, one adds 543 to convert Western-era AD years to Thai BE equivalents. This also means that the second Buddhist Millennium was reached over 500 years ago.

A more significant recent year for traditional Thai Buddhism occurred with the year 1957 AD, equivalent to Buddhist calendar 2500. In traditional Thai lore, that year marked the half-way point between the Buddha’s passing to Nirvana and the predicted end of the current age. Sukhothai inscriptions of 650 years ago relate to this 5000-year time period, containing predictions of progresive upheaval and ultimately deterioration as we progress along the time line—a process of ‘Buddhist entropy’ in which 1957 marked an important half-way point. It was celebrated by the then Prime Minister Phibul Songkhram’s construction of Phutthamonthon, an enormous Buddhist compound outside of Bangkok which now attracts tourists. He also installed huge Buddhist images and even emptied Thai jails and prisons of all but the worst criminals in a widespread amnesty. This 5000-year perspective can be linked to the traditional Buddhist concept of [anicang]: the transitory—and in the long run deteriorating—nature of the material world.

Although some temporal cycles used to keep time, both in Thailand and in the West, may seem matters of astronomical or climatological fact, these cycles tend to accrue cultural significance and local sensibility. Nor are all time cycles or counting systems necessarily based on strict astronomical mechanics, as seen in the 5000-year Buddhist age noted above, or in recent second millennium celebrations in the West. The astronomically ‘arbitrary’ seven-day week, which we see below has deep roots in the Thai region as well as in the West, is surely part of a socio-cultural reality for many urban working people. How many readers of this study experience the passage of time as a repeating sequence of weekdays and weekends? Which is more common: to be unaware of the day of the month or of the weekday?

Anthropologist William J. Klausner (1981:273-5) has considered deeper dim-ensions of cross-cultural temporal contrast, including what it means to be ‘on time’ or ‘late’, with their attendant sensibilities. Klausner calls attention to what Western observers may interpret as a ‘present-oriented’ tendency in some aspects of Thai worldview and social interaction. He also convincingly associates what Westerners may feel to be comparatively lax Thai feelings about personal punctuality with key Buddhist concepts, such as [anicang], mentioned above. In an interesting contrast, another anthropologist, Nerida M. Cook (1993:243), describes Thai astrological practice with its concerns for temporal precision and belief that even small differences in timing can relate to cosmic schemes affecting one’s fate and luck (for good examples in Thai inscriptions, see Eade, 1995:92).

These matters raise general questions as to what extent the passage of time is a cultural construction rather than a natural given. What follows is an attempt to provide a modest preliminary summary for pursuing these questions in the Thai case. Our focus here is to trace a rich calendrical polysynthesis of time-keeping, accumulating from a period of Proto-Tai times of over a thousand years ago to present-day usage in downtown Bangkok. Parts of this account still remain speculative and the writers will gratefully receive corrections or additions.

(Note that the spelling ‘Thai’ here refers to the national language of Thailand. ‘Tai’ refers to the entire language family which includes as members: Thai spoken in Thailand, Lao in Laos, Khamti in India, Shan in Burma/Mianmar, Nung in Vietnam, Zhuang in China and many other varieties. ‘Proto-Tai’ is a scholarly hypothesis—a reconstructed language approximating (as we linguists hope) what was spoken some 1500 years ago in the Xi River region of what is now Guangxi Province in southern China. For convenience in this online presentation, Thai tones are not shown directly in the transcription used here, although vowel length is indicated by colon; diphthongs are also phonologically long. For some items etymological tone class is indicated as explained after example (1.1).)

1. Main temporal unit terms

The main natural givens of a calendrical system, day and night, months and years, are each represented by reconstructable Proto-Tai (PT) forms. In fact, surprisingly, as (1.1) shows, for ‘day’ and ‘month’ PT speakers appear to have used two items for each temporal unit. Since these forms show different ultimate etymological connections, they might be interpreted as evidence for the Proto-Tai community having roots extending in different directions.

(1.1) Basic temporal units

1 2 3 4 5

day wan (A2) *ngw- Austronesian connections?

mu’: (C2) *mw -

night khu’:n (A2) *G Chinese connections?

month du’an (A1) *bl Austronesian connections.

nguat (D2) *ngw- Chinese connections.

year pi: (A1) *p -

(kha:w) (C1/C2) *X [metonymy ‘rice (harvest)’]

In (1.1), column 2 shows the vowel-consonant makeup of Thai words translating terms in column 1. 3 indicates etymological tone class. 4 shows reconstructed Proto-Tai initials, after the method of Li (1977). 5 indicates possible wider relationships. Modern Thai tones are predicted from etymological tone class in column 3 as follows: C2 - high; C1,B2 - falling; B1 - low; A2, A1 (unaspirated-stop initials) - mid; A1 (other initials) - rising. D coincides with B except for short-vowel items in class D2, which show high tone. Thus wan, khu’:n, du’an and pi: are all mid tone; mu’: is high; nguat, phonologically long, is falling. Cognate tones for Lao and other Tai varieties can be deduced from similar sets of rules given by Li (1977).

In the case of ‘year’ there is a well-known metonymy, found in the Sukhothai inscriptions, of using ‘rice’ or ‘rice harvests’ to count years. In the case of ‘day’ and ‘month’, when cognates of both forms occur in a given Tai language, there tends to be some difference in meaning and use. [wan] tends to emphasise daytime and thus to contrast with [khu’:n]; or else to be used to name days of the week. Cognates of [du’an] emphasise the moon as a celestial body, whereas [nguat] suggests a regular monthly span of time. In modern Central Thai, he cognate form has kept its notion of a regular period, but this is now not necessarily a month. It refers instead to a regular repayment or installment.

2. Subdivisions of the day

(2.1) Probably in Proto-Tai.

daybreak rung (B2) *r

morning cha:w (C2) *j

late morning sa:y (A1/A2) *Z? ("Gedney" series)

evening (mealtime) lae:ng (A2) *l (Lao usage; not used in Thai)

evening kham (B1) *G (velar fricative)

(2.2) Probably not in Proto-Tai

late morning phe:n (A1) Pali, a Buddhist term

noon (/straight) thiang (B2) Old Khmer (? Varasarin 1984:313).

afternoon (/inclined) ba:y (B1) etymology unclear

One familiar way of telling time in modern Central Thai combines the earlier forms in (2.1) and (2.2) with numbers followed by forms suggesting how many times a bell or drum has sounded. Thus one way to say "10 am" in Thai is [si: mo:ng chaw] which indicates ‘four bells in the morning’. (2.3) shows that parts of this system were in use in Ayudhyan times, but it was not made entirely uniform until King Chulalongkorn established the official version in 1901 (Royal Gazette 17:206; noticed by Sanguan Ankhong 1959:183). The 1901 system is still in common use, with some minor changes concerning nighttime hours and how to refer to 6 am, 6 pm, and 12 noon. The current system is shown in (2.4).

(2.3) Hour expressions used by the Siamese Ambassador to the Court of Louis XIV (Kosapan 1686; Kongkaew Viraprachak 1985).


so’:ng mo:ng cha:w 8 am

sa:m mo:ng cha:w 9 am

thiang 12 noon

ba:y mo:ng nu’ng 1 pm

ba:y so’:ng mo:ng 2 pm

ba:y si: mo:ng 4 pm

Associated with this system is a larger unit, the [ya:m] or 3-hour ‘watch’. La Loubere (1693; 1986:102) confirmed that this system was in use for dividing the nighttime during the Reign of King Narai. King Chulalongkorn and King Vajiravudh also regularised the use of this unit and one still hears terms like [so’:ng ya:m] ‘midnight’ or [sa:m ya:m] ‘3 am’. In etymology [ya:m] is clearly Indic ‘watch’ but the form has spread to a number of Southwestern Tai languages where Indic influence is minimal, such as Black Tai. A somewhat different usage of hour-and-a-half [ya:m] units is characteristic of some Northeastern (Lao) and Northern inscriptions (Dhavaj Punoothok n.d. For more detail see Eade 1995:93.)

In traditional times, the Thai day began at sunrise for astrologers, but for villagers, when they could see the lines in the palm of their hand. The European system of ordering hours from one to twenty-four, starting at midnight, may have first been adopted by the Thai military. Time of this sort became visually salient in Bangkok when King Mongkut (r. 1851-1868) had constructed a large clocktower, still to be seen near the Ministry of Defence. Later, in decrees of 1917 and 1920, King Vajiravudh established the 24-hour system as the official one, with Thai time set as 7 hours prior to Greenwich (Royal Gazette 36:273; Prasert Na Nagara 1991:134). The Indic astronomical/calendrical term [na:di:], which had referred to a period of 24 minutes, gave rise to Thai [na:thi:], redefined with the modern sense of ‘minute’. The neologism [wina:thi] ‘second’ was added.

The 24-hour system itself, in two sets of 12, is of great antiquity and can be traced back to early Egyptian sources.

(2.4) Current Thai systems of counting hours

official colloquial or folk note

1 AM 1 naalikaa ti: 1 ti: (A1) ‘hit’

2 2 " ti: 2

3 3 " ti: 3

4 4 " ti: 4

5 5 " ti: 5

6 6 " 6 mo:ng cha:w mo:ng (A2) ‘chime’

cha:w (C2) ‘morning’

7 7 " (1) mo:ng cha:w

8 8 " 2 mo:ng cha:w

9 9 " 3 mo:ng cha:w

10 10 " 4 mo:ng cha:w

11 11 " 5 mo:ng cha:w

12 noon 12 " thiang (wan) thiang (B2) ‘noon’

1 PM 13 " ba:y (1) mo:ng ba:y (B1) ‘slant’

2 14 " ba:y 2 mo:ng

3 15 " ba:y 3 mo:ng

4 16 " 4 mo:ng yen yen (A2) ‘cool, eve’

5 17 " 5 mo:ng yen

6 18 " 6 mo:ng yen

7 19 " 1 thum thum (B2) ‘drumbeat’

8 20 " 2 thum

9 21 " 3 thum

10 22 " 4 thum

11 23 " 5 thum

12 midnight 24 " 6 thum


3. Counting days

In Proto-Tai times, I suggest that there were three main three ways of keeping track of days. The first was to use what could be called an egocentric system of terms like ‘today’ and ‘yesterday’. A rich system of terms of this sort can be found in a number of Tai languages, although it is not certain yet how much of the system, and which particular terms, would go back to Proto-Tai. (3.1) compares terms of this type in two widely-separated Tai varieties, belonging to different branches of the family: Southern Thai of the Nakhon Srithammarat area and Nung, spoken north of the Red River in Vietnam (Be, Saul and Wilson 1982 and writer’s fieldnotes).


Southern Thai Black Tai Nung

three days ago’ tae:B1-ru’angB2 - vanA2-mu’nC2

two days ago tae:B1-su’:A2 mu’C2-su’nA2 vanA2-slu’nA2

yesterday rae:kD2-wa:A2 mu’C2-ngoaA2 vanA2-va:A2

today wanA2-ni:C2 mu’C2-niC1 vanA2-nayC1

tomorrow to’:B1-phro:kD2 mu’C2-puC1 vanA2-pukD2

two days hence to’:B1-ru’:A2 mu’C2-hu’D2 vanA2-lu’A2

three days hence to’:B1-ru’angB2 - vanA2-loengB2

four days hence to’:B1-rawA2 - vanA2-litD1

The second system would have been tied to the moon, which we consider again below under months. On a world scale, Marschak and others have found material evidence that counting days by the moon was recorded tens of thousands of years ago by our early ancestors. In Thai we encounter expressions like [rae:m nu’ng kham] ‘first day of the waning moon’, a system important in Buddhist practices. In several Tai languages, including Nung and others with little or no Indic vocabulary or Buddhist influence, days of the lunar month are also counted from New Moon to Full (fifteen days) and back to new, but details and specific forms vary. Even terms for new and Full Moon are different, although the concepts must be universal. Comparative evidence is thus good for some Proto-Tai system of this sort, but sparse as to details of exactly how Proto-Tai speakers would have kept track of days of the lunar month.

(3.2) Tai 60-item day series (after insciptional surces, 14th-16th centuries AD)


1. ka:p 1. cai 1. ka:p-cai 2. dap-plao 3. rawai-nyi

2. dap 2. plao, pao 4. moeng-mao 5. ploek-si 6. kat-sai

3. rawa:i 3. nyi:, ngi: 7. kot-sanga: 8. ruang-met 9. tao-san

4. moeng 4. mao 10. ka:-rao 11. ka:p-set 12. dap-kai

5. ploek, poek 5. si: 13. rawai:-cai 14. moeng-plao 15. ploek-nyi

6. kat 6. sai, su’ 16. kat-mao 17. kot-si 18. ruang-sai

7. kot, khut 7. sanga:, ngo 19. tao-sanga 20. ka:-met 21. ka:p-san

8 ruang 8. met, mot ... (etc.) ...

9 tao 9. san 55.ploek-sanga: 56.kat-met 57.kot-san

10. ka: 10. rao, lao 58. ruang-rao 59. tao-set 60. ka:-kai

11. set, su’t; mit

12. kai, kau’, khai

The third reckoning system for days that the Proto-Tais probably used is the 60-day decimal-duodecimal series, illustrated in (3.2). Decimal and duodecimal cycles repeat independently and are juxtaposed 10 + 12. Although this 60-day system is no longer used in Central Thailand, it is still known in Northern Thailand and is especially common in early inscriptions where it is often identified explicitly as ‘Tai’, e.g. ‘the Tai day is tao-san, the Meng day is Thursday.’ This use of ‘Tai’ seems to be used in an ethnic or ethnolinguistic sense, since it is usually contrasted in the inscriptions with Meng, which most scholars associate with the Mon, or Khom, undoubtedly the Khmer; see below. This impression from the inscriptions that the 60-day system was considered to be Tai in essence is strongly supported by comparative evidence.

Terwiel (1981) and sources cited therein establish the extent of this means of counting days in the Tai area and show that it is motivated partly by a system of lucky and unlucky occasions. This is especially clear in certain Tai-Ahom sources such as lucky-day or [lak-ni] lists. It may be that moveable markets were regulated by these terms and there are also reports of two days of rest per ten-day cycle.

The 60-term cycle undoubtedly has an ultimate relationship with an isomorphic early Chinese practice, but there may be other associations as well. Etymologically, while the majority of duodecimal items have plausible Chinese cognates (7.2), the decimal items do not seem Chinese. During the Shang era (14th century BC) a similar 60-day counting system has been found which was later extended to year-counting by the late Han (2nd century AD). Thereafter, among the Chinese the day-counting function of the terms gradually fell into disuse, with year-counting (and even hour-counting) becoming the popular use of the system. For the Proto-Tais, however, both days and years continued to employ the same sequence, perhaps furnishing a clue as to contact period.

However, before concluding that the 60-item series is simply a cultural borrowing from Chinese, a fuller study of other adjacent traditions needs to be undertaken. For example, it is well-known that Javanese, Balinese and other Austronesian calendrical traditions make use of superimposed cycles. Balinese practice, for example, makes use of repeating 6-item and 5-item sequences, which, if doubled, would be isomorphic to the Tai system. The 6-item series refers to animals and the 5-item one to colours (Sujiati Beratha, p.c.).

Leaving the Proto-Tai era, we turn to the seven-day week familiar to Westerners as it appears in Thailand. In fact, someone learning Thai might be forgiven for assuming that the Thai seven-day week had been recently borrowed from Europe as part of the process of modernisation; compare the 24-hour system discussed above, which is clearly such an import. The Indic-derived names of the Thai days correlate with heavenly bodies, perfectly matching the familiar sequence of French and other Romance languages as in (3.3). We know that many Western lexical items have been assigned neo-Sanskritic names, calques or forms otherwise created by the Thai Royal Institute and similar authorities. Surely the week names would fall into this familiar category?

But this is not the case. These are Sanskrit names of long standing. Over a thousand years ago, before Tai speakers started writing in this area, Khmers and Mons were writing these same Indic weekday names on their inscriptions, perhaps for purposes of astronomical/astrological precision. (For example, a form of ‘Monday’, [candradivasava:ra] occurs in Khmer inscriptions dated to 673 and 684 AD; Jenner 1981:75.) Tais of Sukhothai, Chiangmai and later, of Ayudhya and elsewhere quite naturally adopted this system. It has even been reported in use among less-Indicised Tais such as certain Black Tai groups.

It is interesting that colours and auspicious and inauspicious associations have been imputed to weekdays by some Central Thais, as in (3.3). Could this be a transference of some sort from the older 60-day cycle that probably had similar luck-associated associated beliefs?

To trace the seven-day week briefly backwards in time, evidence indicates that it arrived in India in the first few centuries AD, along with the twelve zodiacal signs (below) and a range of theory and method relating to the Greek system of astronomy. This was epitomised in the work of Claudius Ptolemy, who lived in Alexandria in Egypt (c.100-170 AD). One tradition is that after Christian monks took control of Alexandria in Egypt in about 400 AD, burning its great library and cruelly murdering Hypatia, a female mathematician of great fame, scholars fled from Egypt to India. Sanskrit sources explicitly refer to the Greek astronomers and Greek technical loanwords were adopted (Roebuck 1992:7; Pingree 1981). In fact, the Thai word for ‘astrology’ [ho:rasa:t] is derived from a Sanskrit borrowing at this time derived from Greek [hora] ‘proper time’, cognate (through Latin and French) to English ‘hour’.

However, the Indic tradition had an impressive preexisting expertise in Astronomical matters and elements of the Hellenistic system were grafted into this, as we see below. An interesting Indic addition to the list of celestial beings is Rahu, the invisible monster responsible for eclipses. As we see in section 8 below, Rahu still appears (as number 8) in Thai astrological [duang] diagrams, along with the seven visible celestial bodies associated with weekdays. Rahu’s base position in the seven-day week is put at Wednesday night.

Many scholars agree that the ultimate source of the seven-day week is Babylon, where the Jews accepted it during their captivity (approximately the time of the Buddha), perhaps then projecting this backwards in their scriptures to the 7-day creation of the world. Both Jews and Babylonians may have observed a lunar-based week prototype earlier, with main phases of the moon functioning somewhat like special Buddhist days [wan-phra] in current Thai practice, to which the Babylonian system may even be distantly related. The seven-day week may thus have been a regularisation of the lunar system, where main lunar phases vary between seven and eight days.

In any case, the Hellenistic period brought eastern fashions and cults to Greece and Rome and the seven-day week seems first to have been taken up as an astrological cultic practice—not at first as a civil system. The eruption of Mt Vesuvius (79 AD) covered a wall with graffiti referring to the seven day week and making explicit associations with corresponding Roman and Greek gods and their planets. Not long after this time the system spread to the Teutonic outreaches of the Roman empire and, with proper equations of Teutonic gods, became the English week still in use.

(3.3) Seven-day week, celestial bodies and some related beliefs


(< Sanskrit) Roman Teutonic colour(s) other beliefs

a:thit Sun (Sun) red

can Moon (Moon) white, grey auspicious: paring nails

angkha:n Mars Tiw pink

phut Mercury Woden orange inauspicious: haircuts

avoid marriage

pharu’hat Jupiter Thor green, auspicious: scholarship


suk Venus Fria purple avoid funerals

dark grey

saw Saturn (Saturn) black inauspicious: new house

auspicious: shampoo

A final chapter in the Western story came with the first Christian emperor of Rome, Constantine, who decreed the seven-day week the official system for Rome in 321 AD. (Incidentally, this effectively established the prototype of the official weekend as well, as Sunday became an official day off and Saturday, the Jewish sabbath, a day devoid of normal commercial activities.) As noted above, it was about the time of Constantine or a century or so afterwards that there is firm evidence in India of the seven-day week spreading there. We have noted already its further eastward progress—ultimately to modern Thai usage.

The early Tai association of certain days with fortune and misfortune may have been partially remapped onto the seven day week. Some Thai beliefs regarding days of the week shown in (3.3). Dress in the Thai court formerly observed the colour sequence given by the poet Sunthon Phu (see Phya Anuman Rajadhon, 1968:71; compare Chamnong Thongprasert 2519/1976:178.)

For selecting names for the newborn, particular weekdays were held to correlate with letters of the Thai alphabet in auspicious combinations. In traditional practice, at least in aristocratic circles, if a baby was born, say, on Sunday, to be auspicious, its name needed to begin with a vowel (i.e. with the Thai letter [o’ a:ng], used to support word-initial vowel symbols). King Chulalongkorn was born on a Tuesday, accounting for the palatal ch- letter beginning his name. This traditional system, which slightly upsets Indic alphabetic order, is shown in (3.4) and is based on a description by the preeminent historian Prince Damrong Rajanubhab (see Bunyong Ketthet, 1993:51, whose version however appears to contain typographical errors, which we have tried to correct). In this acount, the indicated lucky letter should preferably begin the name (or for female two-syllable names, begin the second syllable), but it might otherwise occur as second letter or final.

(3.4) Prince Damrong Rajanubhab’s auspicious correlations of day of birth and letter beginning name

Sunday (1) vowels: a, e, i, etc. (with Thai letter [o’a:ng])

Monday (2) velars: k, kh, ng, etc.

Tuesday (3) palatals: ch, etc.

Wednesday (day) (4) retroflex: Thai letters such as [do’ chada:, no’ ne:n]

Wednesday (night) (5) liquids, semivowels: l, r, w, y

Thursday (6) labials: p, ph, m, etc.

Friday (7) dentals: t, d, th, n, etc.

Saturday (8) fricatives: s, h, etc.

Other versions, sometimes quite elaborate, are available in Thai astrology manuals which are still widely consulted when children are born. In one such account (Chamnong Thongprasert 1976:171-3) eight prognostics are associated with days of the week and with letters to be considered when choosing a name, as in (3.5).


de:t montri: mu:la a:yu si: utsa:ha boriwa:n kalakini

Sunday 3 4 5 6 7 1 2 8

Monday 4 7 8 5 6 2 3 1

Tuesday 7 6 1 8 5 3 4 2

Wednesday 4 5 2 1 8 4 7 3

Thursday 8 1 4 3 2 6 5 7

Friday 2 3 6 7 4 8 1 5

Saturday 5 8 3 2 1 7 6 4

Key to (3.5). Numbers refer to groups in Thai alphabet, as in (3.4).

The eight prognostics (colunms):

de:t honour, power (appropriate for males)

si: wealth, prosperity (appropriate for females)

montri: lovable

utsa:ha enduring

mu:la prosperity for self or family

boriwa:n will have a large following of associates and friends

a:yu long life

kalakini AVOID - will bring bad luck

In yet more complex a variant, the prognostics (columns in (3.5)) are further permuted by what are referred to as [daksa] diagrams, which take into account lunar month of birth and year in the 12-year cycle (Eade 1995:107-109).

4. The 27 lunar mansions

Prior to the Greek impact on Indic astronomy, the Hindus had carefully observed the day-by-day progress of the moon through the ecliptic over the course of one lunar month to the next. This gave rise to a division of the background stars and constellations nearby the ecliptic into 27 units, called [nakSatra] or ‘mansions’ of the Indic zodiac, as in (4.1). In cases where a stretch of the zodiac lacked bright stars, other stars or constellations of similar longitude were used to name the mansion, as in mansions 6, 13, 15, etc. in (4.1). An occasional 28th mansion was sometimes added to keep the system accurate. The system was codified to be a reliable way of keeping track of days. (Note that this use of ‘mansion’ differs from how the term is used in western astrology. For convenience, Indic retroflex consonants are shown by capital letters.) Thai tradition has associated different shapes with the star groups (Royal Institute 1982:433)

(4.1) Sanskrit lunar mansions [nakSatra]; cp. Thai [roe:k]


1. açvini: beta, gamma Arietis horse

2. bharaNi: 35, 39, 41 Arietas tripod

3. krttika: Pleiades chickens

4. rohiNi: Aldeberan (alpha Tauri) pig’s jaw

5. mrgaçiras lambda, phi Orionis deer’s head

6. a:rdra: Betelgeuse (alpha Orionis) boat’s "eye"

7. punarvasu: Castor, Pollux (alpha, beta Geminorum) golden boat

8. puSya gamma, delta Cancri boat’s anchor

9. a:çleSa Hydra’s head (delta Hydrae, and others) house

10. magha: Regulus (alpha Leonis) and "sickle" male snake

11. pu:rvaphalguni: delta, theta Leonis female snake

12. uttaraphalguni: beta Leonis ceiling cloth

13. hasta Corvus elbow

14. citra: Spica (alpha Virginis) crocodile’s eye

15. sva:ti Arcturus (alpha Bootis) female elephant

16. viça:kha: Libra umbrella handle

17. anura:dha: beta, deta, phi Scorpionis umbrella

18. jyeSTha: Antares (alpha Scorpionis) male elephant

19. mu:la episilon Scorponis, etc.; Scorpion’s tail small elephant

20. pu:rva:Sa:Dha delta, epsilon Sagitarii howdah

21. uttara:Sa:dha: zeta, sigma Sagitarii horn; plow

(Extra: abhijit Lyra)

22. çravaNa Aquila victory post

23. çraviSTha: Delphinius fishtrap

24. çatabhiSaj Aquarius gold press

25. pu:rvabha:drapa:da: alpha, beta Pegasi hogdeer

26. uttarabha:drapa:da: gamma Pegasi, alpha Andromedae walking-stick

27. revati: zeta Piscium, etc. carp (fish)

Other time units are suggested by this division of the zodiac. Lunar months could be designated by this system, with the mansion of the Full Moon in a given month furnishing the name of the month, as noted below. In addition a unit similar to an hour is obtained by attending to the particular mansion either on the eastern horizon or directly overhead at a given moment (the latter usually called [rkSa] in Sanskrit, cp Thai [roe:k]).

This system was clearly known to writers of 14th century Tai inscriptions, who were interested in auspicious timing. They tended to redefine technical terms slightly, with [roe:k] in Thai referring to the mansions and the Thai form of [nakasat] extended to refer to cyclical years (i.e. a particular animal year) as below (7.1).

5. The twelve months and the zodiacal constellations

Like the early Hindus, the Babylonians were keen astronomers. However, instead of dividing the zodiac into lunar mansions as the Hindus did, it is likely that they were responsible for first dividing it into the twelve solar-based zodiacal constellations familiar in the West. Greece and then Rome adopted the system through early contact. It was passed on to India along with the seven-day week, as above, where it was superimposed over the earlier lunar mansions, as though the same star groups now had two ways to be interpreted.

There were now two ways to refer to months, lunar and solar (hence the calendar could be referred to as ‘luni-solar’). Twelve of the lunar mansions were selected to name twelve lunar months, the month-names derived from the [nakSatra] names by undergoing a Sanskrit phonological lengthening process (vrddhi). Thus, for example, the month Caitra was named as the lunar month when the Full Moon occurred near the [nakSatra] or [roe:k] star Citra (i.e. Spica, or alpha Virginis). This would have been approximately during the solar month of Aries the Ram (March-April), where the sun would be opposite the Full Moon.

The Hindus did not use the Western or Babylonian zodiacal terms as phonetic borrowings, but translated them into Sanskrit, e.g. Aries the Ram = Sanskrit [meSa] ‘ram, sheep’. —And so forth for the other zodiacal constellations, although some, like Aquarius, have shifted in significance (‘water-carrier’ to [kumbha] ‘water pot’ or even to ‘potter’; sometimes confused with Skt. [kumbhi:ra] ‘crocodile’). The difference between siderial and tropical signs is discussed below.

(5.1) Sanskrit luni-solar versions of ecliptic divisions; siderial vs tropical zodiac

Constellation of Sun Progressed Sign Position Lunar month

Indic (siderial) Western (tropical) of Full Moon Central Northern

1. mi:na (=Pisces) Aries caitra 5 7

2. meSa (=Aries) Taurus vaiça:kha 6 8

3. vrSabha (=Taurus) Gemini jyaiSTha 7 9

4. mithuna (=Gemini) Cancer a:Sa:Dha 8 10

5. karkaTa (=Cancer) Leo çra:vaNa 9 11

6. simha (=Leo) Virgo bha:drapada 10 12

7. kanya: (=Virgo) Libra a:çvina 11 1

8. tula: (=Libra) Scorpio ka:rttika 12 2

9. vRçcika (=Scorpio) Sagittarius ma:rgaçi:rSa 1 3

10. dhanus (=Sagittarius) Capricorn pauSa 2 4

11. makara (=Capricorn) Aquarius ma:gha 3 5

12. kumbha (=Aquarius) Pisces pha:lguna 4 6

In Thai usage, an adapatation of the base form of the [roe:k] can be used to name the lunar month (rather than using a derived vriddhi form as in Sanskrit). These month names are shown in the right column in (5.2), where it must be emphasised that the lunar months correlate only approximately, sometimes varying by one in either direction. Some of these names, such as for the 6th lunar month, Thai [wisa:kha], are well-known; however other names would be known only by Thai astrologers (Prasert Na Nagara 1998:524).

The suffix [-ma:t], from Indic ‘month’, can added so as to differentiate a [roe:k] (one of 27) from a lunar month (one of 12)—the [roe:k] in or near which the particular Full Moon occurs. Hence, (4.1) indicates that for [roe:k] 5 the Sanskrit name is [mrgaçiras] ‘deer-head’. This refers to a group of stars in Orion, including lambda and phi Orionis, portrayed as the ‘deer-head’ stars. This name is altered by vrddhi lengthening, as (5.1) shows, to [ma:rgaçi:rSa] when the lunar month is indicated, viz, the first lunar month by Central Thai reckoning. This refers to a Full Moon occurring near the designated part of Orion, which most frequently happens in December. For Thai then, this difference in terminology could optionally be shown by the forms [maru’khasira] and [maru’khasira-ma:t] respectively. However, the common Thai practice is simply to refer to lunar months by number, e.g. [du’an s:am], ‘third lunar month’. For the first and second lunar months, the older Tai counting forms [a:y] and [yi:] are used. Thus the first lunar month is commonly [du’an a:y], equivalent in more obscure astrological parlance to [maru’khasira-ma:t]

Summarising then, we note that [roe:k] names have two Indic interpretations (star groups and lunar months), as do Sanskrit zodiac names (star groups and solar months, i.e. periods when the sun is in a particular zodiac constellation). In Thai, yet a third use of the Indic set of solar zodiacal names is far more familiar, illustrated in (5.2), third column. This usage is as exact translational equivalents of the Roman month names, standard in the West since Imperial Roman times: ‘January, February’...’, i.e. in Thai [mokkarakhom, kumphaphan...].

The main feature differentiating the Roman (i.e. Julian, then Gregorian) calendar from the pre-Western Sanskrit, Khmer and Thai system was the Roman uncoupling of calendrical months from the moon. According to classical traditions, Julius Caesar regularised the Roman calendar by alternating 31 and 30 days for odd and even months respectively, counting from March, the traditional first month of the Roman calendar. The moon played no role in this count. He also instituted the leap year system, with 28-29 days for February. Julius Caesar then renamed the fifth month (starting from March) after himself as "July". We have his nephew, Caesar Augustus, to thank for upsetting the alternating system. Augustus, renaming the sixth month of Sextilis after himself (our "August"), changed its count from 30 to 31 days, reportedly to avoid feeling slighted. This system, also used in colonial India, was officially established in 1889 by King Chulalongkorn when other attributes of the Western calendar were adopted. Note that suffix [khom] indicates a 31-day solar month, [yon] a 30-day one.

In the Thai context, these modifications included regularising leap year days as in Western usage, following Pope Gregory’s reform of the Julian system (hence the ‘Gregorian Calendar’). Prior to 1889, traditional Thai practice had in fact recognised the need for extra leap-year like days, called [athisurathin]. Their addition was specified by a rather complex principle involving a variable called the [kammacubala] (see Eade 1995:11; 47 and Prasert Na Nagara 1991:134).

(5.2) Modern Thai solar and lunar months

Indic source Western equivalent Modern Thai Approximate Thai

Gregorian month Gregorian month lunar month

1. makara January mokkharakhom 2. (yi:) busya

2. kumbha February kumphaphan 3. ma:kha

3. mi:na March mi:nakhom 4. phalakhun

4. meSa April me:sa:yon 5. citra

5. vrSabha May phru’sapha:khom 6. wisa:kha

6. mithuna June mithuna:yon 7. che:ttha

7. karkaTa July karakada:khom 8. a:sa:t

8. simha August singha:khom 9. sara:wana

9. kanya: September kanya:yon 10. phatrabot

10. tula: October tula:khom 11. asawayut

11. vRçcika November phru’sacika:yon 12. kattika

12. dhanus December thanwa:khom 1. (a:y) maru’khasira

A number of traditional Thai Buddhist festivals and other events are determined by the phases of the moon, as shown in (5.3).

(5.3) Thai holidays and festivals regulated by the moon

Lunar month phase occasion

3 ma:kha new Chinese New Year*

3 ma:kha full Ma:khabu:cha:

6 wisa:kha full Wisa:khabu:cha

8 a:sa:t full A:sa:lahabu:cha:

8 a:sa:t full + 1 Khaw Phansa: (Start Rains Retreat)

10 phatrabot last day Sa:t, food-cake presentation

11 asawayut full O’:k Phansa: (End " )

11 asawayut full + 1 Kathin pilgramage

12 kattika full Loi Krathong

*Because Chinese New Year is not set by Thai authorities, but depends on international custom, different methods of determing intercalary months will sometimes cause this festival to occur a month earlier or later from the above.

A technical problem arises with the terms ‘siderial’ and ‘tropical’ in (5.1) due to the precession of the equinoxes. The equinoxes are points on the ecliptic where the sun is located when day and night are exactly equal in length. The Spring or Vernal Equinox has been widely taken to be the starting point of the solar year. As Hipparchus (c. 150 BC) and other astronomers of antiquity realised, the equinoxes gradually slip backwards through the zodiac at the rate of about one constellation in two thousand years (50.3 seconds or arc per year).

In terms of reconciling this fact with the establishment of zodiacal constellations, there are two possibilities for practical time-keeping purposes: (i) ignore the precession of the equinoxes and continue to note when the sun enters a particular star group; (ii) ignore the actual stars where the sun is located and instead continually redefine the sign relative to the shifting Vernal Equinox. Thus "Aries" can either mean either (i) the group of stars traditionally seen as the figure of a ram—the actual star group— or (ii) the 30-degree region of the ecliptic immediately following the Vernal Equinox—wherever that may fall. After adopting the Western (or Babylonian) zodiac, the Hindu astrologers opted for (i), while the Western astrologers opted for (ii). For India, this effectively stabilised the definition of the Greco-Hindu zodiac for a Vernal Equinox value of about 400 AD (near alpha Arietis), while the Western zodiac has continued to slip backwards, and is presently on the Pices-Aquarius line, in terms of actual stars. Incidentally, this difference can be interpreted as evidence for about 400 AD as the period when the 12-constellation zodiac came into widespread usage in India.

The above account explains why the Thai version of the zodiac, following (i) and called ‘sidereal’, differs some from the Western one, following (ii) and called ‘tropical’, as indicated in (5.1) and (5.4). As an example, for the date 7 December, the sun will actually be located in the star group Scorpio (Skt. vRçcika; Thai phru’sacak) by system (i); but by system (ii), the sign will be considered by Western astrologers to be Sagittarius (Skt. dhanus; Thai thanwa:). At present, a difference of 23 days has accumulated between the two systems (Prasert Na Nagara 1981:135). It is interesting that Thai popular publications, such as astrology columns in newspapers, sometimes show traditional Thai-Indic dating for zodiacal sign periods, sometimes Western (see 5.3).

(5.4) Comparison of Thai / Indic and Western definitions of zodiacal periods


1. fish 15 March - 12 April 19 February - 20 March

2. ram 13 April - 14 May 21 March - 19 April

3. bull 15 May - 14 June 20 April - 20 May

4. twins 15 June - 15 July 21 May - 21 June

5. crab 16 July - 16 August 22 June - 22 July

6. lion 17 August - 16 September 23 July - 22 August

7. maiden 17 September - 16 October 23 August - 22 September

8. scales 17 October - 15 November 23 September - 22 October

9. scorpion 16 November 15 December 23 October - 22 November

10. bow / archer 16 December - 14 January 23 November - 21 December

11. sea monster / goat 15 January - 12 February 22 December - 18 January

12. pot / water carrier 13 February - 14 March 20 January - 18 February


6. Intercalary months and days

Returning in time to the Proto-Tai era of perhaps 1500 years ago, what can be said of month reckoning? It would appear that the Proto-Tais numbered lunar months consecutively from one to twelve, as discussed in the preceding section. They may well have the system of alternating 29 and 30 day lunar months ([du’an kha:t] and [du’an thuan]) still used in Thailand—similar to systems found in early Babylon, India and China.

Both the Indian astronomers and their Khmer followers counted days in terms of lunar months, with the familiar system of counting 15 days of the waxing moon until full and another count of waning days. The latter count varied: 15 days for even-numbered months and 14 for odd-numbered ones, giving monthly totals of 30 and 29 respectively. As noted above, the Proto-Tais may have used a version of this system but the evidence is unclear.

As (5.1) indicates, as Tais came into contact with details of the Indic system, probably in a Buddhist context, there was some difference in how Indic months were equated with the Tai numbering system, with the Central Thai system beginning the count with the Indic lunar month of [ma:rgaçi:rSa] (Thai [maru’kkhasira]) usually November-December, but with Tais of the Chiangmai area beginning the count two lunar months earlier [a:çvina]. (Some inscriptions show an in-between system beginning in [ka:rttika], referred to as the Kengtung system, see Eade (1993)).

Apart from superficial mismatches in month numbering, intercalary days and months raised more substantial technical problems, sometimes even with political consequences (see section 9).

To begin with, alternating 29 and 30 days for lunar months, [duan kha:t] and [du’an thuan] respectively, gives only an approximate solution to the problem of reconciling lunar months with standard earth days: the moon takes 29.5306 days to complete an astronomical month, so averaging [duan kha:t] and [du’an thuan] gives a result slightly too slightly short, which will accumulate. More fundamental is the shortfall between twelve lunar months (totalling 354 days, 8 hours, and some minutes) and the solar year (365 days, 5 hours, and some minutes). Nearly 11 days per year are needed to reconcile these cycles, i.e. about 33 days per 3 years, or a bit more than one lunar cycle. A corrective sequence might then add an extra 30-day month every three years, but sometimes the extra month would be needed after only two years. In Thai practice, a further minor adjustment was made about once in five years by adding an extra day. (For more detail and comparison with Burmese practice, see Eade 1995 ch. 7.)

In traditional usage within the Thai cultural milieu, there were different means determining which years were to have extra months [athikama:t] and extra days [athikawa:n], rendering the dating of traditional sources a complex task. The common method currently used is the so-called Buddhist method, set out in a manual of Luang Wisandarunkorn (Prasert Na Nagara, 1991, 1998). We slightly reinterpret this system here by supplying Western constellation names. The rules are based on two principles concerned with Buddhist holiday A:sa:lahabu:cha: (5.3) and the following day, the beginning of the Buddhist Rains Retreat ([phansa: or ‘Buddhist lent’). The Rains Retreat is to begin (i) on the first day after the Full Moon of the lunar month of [a:sa:t] and (ii) when the moon is located in the constellation of Sagittarius, somewhat widely defined. This is equivalent to [roe:k] 20 to 22 as in (4.1); astronomically between 253° 20’ and 293° 20’, in one system at least (Eade 1995:33).

To determine whether a given year is normal or requires extra intercalary months or days, first the position of the Full Moon of the 8th lunar month is calculated or determined from ephemeris tables. For a normal year, on the day after the 8th Full Moon, the moon needs to be in [roe:k] 20 to 22 (i.e. in Sagittarius). If this is the case, the year is declared normal, with twelve lunar months of 29 and 30 days, alternating.

However, if on the specified day after the Full Moon, the moon has not yet reached [roe:k] 20, i.e. it is still in Scorpio, then there are two possibilities.

(i) If the moon is only one day’s journey short of Sagittarius (i.e. is located in the [roe:k] 19, i.e. in [mu:la], the tail stars of Scorpio) then the year is to be [athikawa:n], with an extra day to be added at the end of the 7th month. This extra day effectively allows the moon to progress and be relocated in [roe:k] 20 on the day of beginning the Rains Retreat, as the rule specifies. (This would entail the astronomical Full Moon occurring somewhat earlier than usual in the 1-15 waxing sequence, as the particular 8th month would begin somewhat later.)

(ii) If instead the 8th Full Moon of the year is calculated to fall further short (i.e . is located farther back in Scorpio than one [roe:k]), then the year is [athikama:t] with an extra 8th month of 30 days decreed, referred to as [du’an pae:t 2 hon] or [du’an pae:t lang]. The festival A:sa:lahabu:cha: is then held on the Full Moon day of this second 8th month and the beginning the Rains Retreat is then be set at the day after, in which the moon would be in Sagittarius as specified.

A different [suriyaya:t] method was used to determine intercalary months in royal courts of former times (Prasert Na Nagara 1998:522). The phase of the moon at the change of the Chulasakarat year at the Songkran festival was determined. If this was New Moon plus or minus five (or six?) daily phases, the year was to be [athikama:t], with an extra 8th month. Otherwise the year was normal, although [athikawa:n] days seem to have been occasionally added according to procedures not well understood. (See also Eade, 1995, ch. 7).

A final complication: as noted above, traditional Thai practice added solar leap-year days, referred to as [athikasurathin], as well as lunar-based [athikawa:n] days. Exactly how these two sorts of added extra days worked together in practice requires further study.

Traditional Thai beliefs include the preference for even-numbered months for weddings. A well-known manual of royal ceremonies for each of the twelve lunar months was written by King Chulalongkorn.

7. Years

The period of the planet Jupiter is nearly 12 years and that of Saturn nearly 30 years. The two planets thus come into a close cyclical alignment every 60 years. There is some evidence that this fact gave rise both to 12 year cycles and to 60-year cycles in Babylon, India (the ‘Jupiter Cycle’) and China, but the nature of any connections among these traditions remains obscure. Note also that the sunspot cycle is between 11 and 12 years, with some alleged effects on weather patterns. As in the early Chinese practice, the Proto-Tais appear to have used the same 60-item cycle shown in (3.2) to count both days and years.

(7.1) Twelve-year cycle terms compared


rat chuat cai zi

ox chalu: pao chou

tiger kha:n nyi: yin

hare tho’ mao mao

dragon maro:ng si: chen

snake maseng sai, su’ si

horse mamia sanga:, ngo wu

goat mamae met wei

monkey wo’:k san shen

cock raka: lao you

dog co’: set, su’t shu

pig kun kai, kau’ hai

The year-counting use of the Tai form of the cycle is widespread throughout the family (Li, 1945). It is especially common in Northern Thai and Northeastern (or Lao) inscriptions. Gedney (1982) has documented the series in Saek and in other Tai languages of the Northern branch—which show some extra complexity in terms of alternate forms. In Sukhothai sources and in those to the south the Tai forms were abandoned in favour of corresponding Austroasiatic and Indic terms, including a Austroasiatic version of the twelve calendrical animals, as in (7.1). When Tais came into contact with Indic dating system as used by Mons and Khmers these systems were readily adopted. However, to the north, at least, the tendency was to specify Tai years in the 60-item as well as Indic era.

The 12-year animal cycle is important for Thai people as a way of measuring off periods of a life span; hence important transition points. The word [ro’:pD2] "cycle" is used for this purpose. Thus ‘3rd cycle’ is middle-age (36 years old); ‘5th cycle’—time to think about retirement (60 years old), etc. Other folk beliefs relate to relations among spouses or lovers. Spouses born in Rat and Pig years will get along well, in peace and prosperity; Rat and Horse, less peaceful, but ultimate cooperation in bringing up the family. Yet another set of beliefs relates to climate, and may have regional manifestations. For rural Southern Thais, the Dragon years are likely to be very wet.

The first of the Indic eras to be used in Tai inscriptions was Mahasakarat, which had been in regular use for centuries in Old Khmer inscriptions. Its era started in 78 AD and was associated with the King Kanishka of the Çaka people. The Thai suffixal expression [-sakara:t] literally ‘(year of) king of the Çakas’, was used first to mean ‘Çaka era’, then through metonymy came to be regarded as a suffix meaning ‘era’ in general. Finally, the related Thai loan form [sok] was further reinterpreted to mean either ‘year of a decade’ in compounds (see below) or simply ‘year’ in certain fixed expressions: [sok ni:] ‘this year’.

In use slightly later was Chulasakarat, starting in 638 AD, apparently invented on abstract theoretical principles centuries after the date itself on the initiative of Mon or Burmese astrologers. This era gained in clerical and administrative popularity until it became the standard from Ayudhyan times to the reign of King Chulalongkorn; it lingers on in special ceremonial uses.

It could be argued that the Tais of Ayudhya did not totally abandon the Tai 60-year cycle but rather recast it into in Austroasiatic-Indic form. In calendrical expressions it was normal to cite the Austroasiatic form of the 12-year animal cycle, e.g. as [pi: kun] ‘Year of the Pig’ and then to add a 10-year extension like [sapatasok] meaning ‘Seventh year of the decade’, i.e. a Chulasakarat date ending in the digit -7, such as C.S. 1357; see (7.3). Although the 12-10 ordering in expressions like [pi: kun sapatasok] is the reverse of 10-12 Tai-style [dap-kai], this new combination is still effectively a direct analogue of the original 60-term Tai system.

(7.2) Chuasakarat final digit and 10-item cycle


first sixth kat ji earth

second seventh kot geng metal

third eighth ruang xin "

fourth ninth tao ren water

fifth completed ka: gui "

sixth first ka:p jia wood

seventh second dap yi "

eighth third rawa:i bing fire

ninth fourth moeng ding "

completed fifth ploek mou earth

(7.3) Comparison of year dating sysems


2535 1992 1354 tao-san 4th wo’k 9th

2536 1993 1355 ka:-lao 5th raka: 10th

2537 1994 1356 ka:p-set 6th co’: 11th

2538 1995 1357 dap-kai 7th kun 12th

2539 1996 1358 rawa:i-cai 8th chuat 1st

2540 1997 1359 moeng-plao 9th chalu 2nd

2541 1998 1360 ploek-nyi: 10th kha:n 3rd

2542 1999 1361 kat-mao 11th tho’ 4th

2543 2000 1362 kot-si: 12th maro:ng 5th

(After Dhavaj Punoothok, n.d.:181).

While most features of the Gregorian calendar were adopted in Thailand in 1889, Western year dating in AD was not. (Note however that AD dating is now regularly used in Laos.) In Thailand, Chulasakarat dating first gave way to Ratanakosinsok, (commemorating the Ratanakosin Dynasty’s founding in 1782 AD; 1781 is the usual conversion factor, but the Thai year number at this time changed at the Songkran Festival in mid-April.) Only thirty years later, there was a shift to the presently-used Buddhist Era, instituted officially under King Vajiravudh in 1912 (Royal Gazette, 29:265).

In fact, Buddhist Era (BE) was by no means a new system in the Tai world. As we saw in the Prologue, the 14th century writings of King Lithai and other inscriptional sources devote detailed attention to "placing" the present moment within the 5000-year era between the Buddha’s passage to Nirvana and the end of the current age of the world. As King Vajiravudh noted in his comments on the law, Buddhist Era had been known and used from earliest times in religious contexts. The institution of BE dating thus should not be seen as a stark innovation based on a simple transposition of the dominant the Western AD prototype, but rather should be seen as a functional expansion: turning BE dates to use for practical secular dating.

As to where to start reckoning new years, the Thais in the past have had a range of usages but the original Proto-Tai situation is unclear. The Chinese New Year is associated with the New Moon most frequently falling in February and this festival is widely celebrated in Thailand, although not officially. As noted in Section 6, the traditional Thai agricultural new year started earlier—with the New Moon in November-December after the ‘Loi Krathong’ Full Moon (normally the twelfth one of the year) and coinciding with the end of the floods. Buddhist usage and rural Thai villagers still refer to ‘the fifth month’, ‘he eighth month’, etc., in terms of this particular lunar ordinal count. But this reckoning works only for Central Thailand: the September-October New Moon, two months earlier, traditionally was taken as the beginning of the lunar year in Chiangmai and the North (see 5.1).

The Indic new year, important for court rituals and the traditional time to shift the Chulasakarat number, was the Songkran festival at the end of the rice harvest in mid April. Rituals included offering a ceremonial ox a range of foods, with the food selected presenting a prognosis for the coming year. Songkran is now called "the Thai New Year" and is fixed at 13-15 April. This period is currently celebrated in Thailand, no longer through a calendrical increment but rather as a public holiday during which Buddhist images are cleansed and water is freely splashed on all and sundry. The final adjustment of changing the time of the year’s increment from Songkran to the first of January was accomplished by Prime Minister Pibunsongkram in 1941. That was the last official systematic change to the Thai calendrical system now in use.

To achieve technical accuracy in dating, the 1941 change must be kept in mind when using the conversion factor 543 to change AD years to BE ones. For pre-1941 dates in January or February, the conversion factor is rather 542, reflecting the fact that the older Thai calendar then in use had not yet reached Songkran, at which time the year number was changed. For dates in March or April, the problem becomes even more difficult, as one first must determine when Songkran for the particular year occurred. Depending on the era involved, this may require consideration of the lunar calendar, and hence of intercalation matters discussed above.

8. Calendrical diagrams

Traditional manuscripts, and even modern Thai newspapers, make use of at least two sorts of calendrical diagrams, shown below.

Figure (8.1) shows a traditional dating method with Thai numerals, above, translated into Arabic numerals below. Three numerals are grouped around a ‘phaya:n:’ sign, looking somewhat like a seven. The date indicated is read: ‘fourth day of the week, sixth day of the waxing moon, fifth month’. Sunday is considered the first day of the week. ‘Fifth month’ in this case refers to lunar months as ordered in the ‘Central’ column of (5.1). Waxing-moon days are shown by placing a number above the ‘pha:yan’; waning-moon days, below it.

Figure (8.2) shows a ‘duang’ diagram still widely used in Thai astrology and not entirely unlike Western horoscope charts. Segments in the circle represent the twelve zodiac constellations, starting with Aries at the top (i.e. as recognised in Thai usage; see (5.1)) and proceeding counter-clockwise around; the Thai Taurus is thus in the ‘11 o’clock’ position. Numerals in segments show which heavenly bodies are in zodiacal constellations at the time represented by the ‘duang’. Numbers are associated with the week sequence: 1 = Sun; 2 = Moon; 3 = Mars; 4 = Mercury; 5 = Jupiter; 6 = Venus; 7 = Saturn. 8 represents the demon Rahu, an invisible ‘planet’, actually a lunar node, accounting for eclipses. The particular ‘duang’ shown here is for 31 December 1999. Calculations are based on Eade (1995), for which see for further detail.

Duang diagrams appear on Lanna (Northern Thai), Mon, and Burmese inscriptions well before the coming of Europeans to Southeast Asia. It is likely that the resemblance of duang diagrams to Western horoscopes in form and function is related to the same basic transmission factors accounting for the shared seven day week and the 12 constellations of the zodiac. To trace this convergence in detail, we must look to early links between India and the West—especially between Hellenistic centres of learning such as Alexandria and Babylon and sites of Hindu astronomical learning, such as Ujain (Pingree, 1981).

For important studies of what duangs of this sort may mean for Thai personality, politics and culture, see Cook (1989, 1991). She elaborates the way in which not only people, but nations and dynasties, have duangs in which their destinies can be read by those adept in Thai astological lore.

9. Conclusion

The preceding sections have summarised the main features of what we have been able to trace regarding Proto-Tai time-keeping and how the current calendrical system used in Thailand has gradually evolved. For purposes here, we have tried to emphasise early versions of "globalization" and cultural interchange that lie behind the accretions constituting calendrical practice, from Proto-Tai times down to modern Thai usage.

A finding of interest, related to the historical synthesis mentioned, is the high degree to which Thai culture espouses multiple ways of coding basic time units. Two systems are widely used to count hours (2.4). Solar, lunar and seven-day counts are in use to keep track of days, correlating with lunar and solar months. Years are commonly counted both by the Buddhist Era and by the 12-year animal cycle. Finally, there are at least four Thai new-years possibilities: the inception of lunar month one, often in December; secular (Western) New Year’s Day of 1 January; Chinese New Year, often in February, and Songkran, the earlier wendic-associated year change when the sun enters Aries, now fixed in mid-April. Usage of these different timing systems will refer to important features in contemporary Thai society: urban vs rural culture; Buddhist observances; official vs informal use, etc.

But further questions now arise. How political control has been exercised relating to these matters is an important matter to explore. wet is said, for example, that King Lithai and King Prasat Thong each ordered special calendrical adjustments, but the exact status of these remains unclear. Note also the report in the Luang Prasert Chronicle that the Burmese once ordered Ayudhya to annul a particular intercalary change. What could be called the political hegemony over time-keeping is certainly an area of research worth more attention. Other areas to explore are the more anthropological aspects of time-keeping, including the observance of festivals, ceremonies and temporal tabus (see Terwiel 1981) and of how personal and national destiny are experienced as part of the flow of time (Cook 1989, 1991).


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