Casting the horoscope or astrological chart and locating the Ascendant is the most important issue in the principle of Thai astrology.
In essence. –
Prediction of a person cannot be made without casting birth chart and locating the native’s Ascendant.
Wrong casting or mislocating the Ascendent will also result in wrong prediction.
In casting birth chart correctly, it is necessary to know the native’s exact birth date and birth time.
In the old days, casting astrological chart is quite difficult process due to daily change in planetary position of the ten planets.
The planetary positions will be calculated one year in advance by four astrologers and under reviews by 4 official astrologers (patronage by the King).
All information or ephemeris is recorded in manuscript called Khoi Book (Thai ancient long papers made up of pulp) for two sets.
One set will be kept in the National Library, the other will propose to the King for use in the royal court.
In the old days, casting horoscope and locating the Ascendant were difficult process by use of manual calculation based con complex formula.
Therefore, the use was mainly for royal affair, important ceremony, war affair.
About 1940, some person asked to copy this ephemeris from the National library. According to the history, it takes several people to sit and jot down copies for months.
The ephemeris called “Astrological calendar” then was published and sold to the public.
Since then, Thai astrology knowledge has been prevailed to the public.
However, casting horoscope and locating the Ascendant are will difficult to general public due to lacking the number of capable astrologers.
Later, there was an inventor of a spinning disc called “Complete Ascendant Plate”, used for locating the Ascendant easily.
The plate is used in conjunction with the Astrological calendar for casting horoscope chart with locating the Ascendant.
Nevertheless, casting horoscope and locating the Ascendant are considered as the high-class job, which required highly skilled astrologers.
In the past ten years, the popular use of computer and interest in casting horoscope resulted in the ease of casting horoscope and locating the Ascendant to general public.
There have been lots of programmers and developers creating programming for casting horoscope and locating the Ascendant by few minutes.
Nowadays, there are lots of astrological application invented by several developers based on different form, methodology, and formula for calculation of planetary position calculation.
Planetary positions of some application might be slightly different at certain date and time.
This is because the formula used to calculate planetary position are not from actual planetary orbit but from the perspective of observation of people from earth.
The formula for calculating such planetary positions has been developed continually since ancient times by astronomers and astrologers from several nations and languages.
The compilation of formula has lots of diversity until nowadays. Some formulas have been kept secretly with developers and not been distributed to general public.
Therefore, the formula for calculating can be different.
For Thai astrology, the formula of Master Thongchua Angkaew is acclaimed as the most accurate and standard use amongst Thai astrologers.
He devoted his whole life to study Thai/International/Hindu/German/Arabic astronomy and Thai astrology and invented and developed Thai ephemeris for Thai astrologers’ community.
Although he passed away several years ago, he has an heir who has continued to publish Thai ephemeris. This is of great contribution to Thai astrology.
Master Thongchua Angkaew devoted his 20 years for manual calculation the Thai ephemeris by use an old calculator.
The planetary positions and other notes are collected and published in a book called “Astrological Calendar” with three editions, a total of 100 years ephemeris, 10 years ephemeris and an annual ephemeris (astrological diary).
His time came before computerized calculations as in all astrological applications nowadays.
Despite its origin from other country, casting an astrological chart and locating the Ascendent for Thai astrology will base on reference location in Thailand, to the place at Khong Chiam District, Ubon Ratchathani Province.
This location is the eastern end of latitude in Thailand, where it receives the first sunlight of the day. All planetary positions are calculated based on that location.
Therefore, casting astrological chart and locating the Ascendant for whom born other places require deducting minutes the sunlight appear in that local location after that of reference place from the clock time (standard time).
We call this process as local time adjustment.
For example. – A person who born in Bangkok at 12.00 will have to subtract 18 minutes and result in 11.42 which we use this time for casting astrological chart and locating the Ascendant.
Therefore, to casting astrological chart for a person who born in the US, we need to subtract time about 12 hours from Thailand standard time.
A person who born at noon in the US will appear to born at night when casting astrological chart or even worse might require reduction of birthday by one day.
This problem will be apparent in vast area country such as China (despite 5 time zones, it uses the single time of reference at Beijing for the country standard time).
As can be seen, the time adjustment process for local time is quite difficult and complex.
The local time adjustment is one of the main reasons that Thai astrology has limit use in Thailand and in doubt whether can apply worldwide.
However, my Thai astrology subject require no local time adjustment.
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