Growing up in a conservative family, I saw my community elders choose a good day for events or celebrations.
Including, a good day to travel, a good day to start a business, a good day for haircut and much more.
Do they adopt animism? Or is it related to Buddhism?
According to DN 2, calculating auspicious dates is considered an "animal art" and wrong livelihood. It is prohibited for monks:
"Whereas some contemplatives & brahmans, living off food given in faith, maintain themselves by wrong livelihood, by such "animal" arts as: calculating auspicious dates for marriages — both those in which the bride is brought home and those in which she is sent out; calculating auspicious dates for betrothals and divorces; for collecting debts or making investments and loans ... — he abstains from wrong livelihood, from "animal" arts such as these.
There are plenty more such "animal arts" in the sutta, including astrology, geomancy, palmistry, omen reading, dream interpretation, magic etc.:
"Whereas some contemplatives & brahmans, living off food given in faith, maintain themselves by wrong livelihood, by such "animal" arts as: reading marks on the limbs [e.g., palmistry]; reading omens and signs; interpreting celestial events [falling stars, comets]; interpreting dreams; reading features of the body [e.g., phrenology]; reading marks on cloth gnawed by mice; offering fire oblations, oblations from a ladle, oblations of husks, rice powder, rice grains, ghee, and oil; offering oblations from the mouth; offering blood-sacrifices; making predictions based on the fingertips; geomancy; making predictions for state officials; laying demons in a cemetery; placing spells on spirits; earth-skills [divining water and gems?]; snake-skills, poison-skills, scorpion-skills, rat-skills, bird-skills, crow-skills; predicting life spans; giving protective charms; casting horoscopes — he abstains from wrong livelihood, from "animal" arts such as these.
"Whereas some contemplatives & brahmans, living off food given in faith, maintain themselves by wrong livelihood, by such "animal" arts as: determining lucky and unlucky gems, staffs, garments, swords, arrows, bows, and other weapons; women, men, boys, girls, male slaves, female slaves; elephants, horses, buffaloes, bulls, cows, goats, rams, fowl, quails, lizards, rabbits, tortoises, and other animals — he abstains from wrong livelihood, from "animal" arts such as these.
"Whereas some contemplatives & brahmans, living off food given in faith, maintain themselves by wrong livelihood, by such "animal" arts as [forecasting]: the rulers will march forth; the rulers will not march forth; our rulers will attack, and their rulers will retreat; their rulers will attack, and our rulers will retreat; there will be triumph for our rulers and defeat for their rulers; there will be triumph for their rulers and defeat for our rulers; thus there will be triumph this one, defeat for that one — he abstains from wrong livelihood, from "animal" arts such as these.
"Whereas some contemplatives & brahmans, living off food given in faith, maintain themselves by wrong livelihood, by such "animal" arts as [forecasting]: there will be a lunar eclipse; there will be a solar eclipse; there will be an occultation of [a conjunction of the moon or a planet with] an asterism; the sun and moon will be favorable; the sun and moon will be unfavorable; the asterisms will be favorable; the asterisms will be unfavorable; there will be a meteor shower; there will be a flickering light on the horizon [an aurora?]; there will be an earthquake; there will be thunder coming from dry clouds; there will be a rising, a setting, a darkening, a brightening of the sun, moon, and asterisms; such will be the result of the lunar eclipse ... the rising, setting, darkening, brightening of the sun, moon, and asterisms — he abstains from wrong livelihood, from "animal" arts such as these.
"Whereas some contemplatives & brahmans, living off food given in faith, maintain themselves by wrong livelihood, by such "animal" arts as [forecasting]: there will be abundant rain; there will be a drought; there will be plenty; there will be famine; there will be rest and security; there will be danger; there will be disease; there will be freedom from disease; or they earn their living by accounting, counting, calculation, composing poetry, or teaching hedonistic arts and doctrines [lokāyata] — he abstains from wrong livelihood, from "animal" arts such as these.
"Whereas some contemplatives & brahmans, living off food given in faith, maintain themselves by wrong livelihood, by such "animal" arts as: calculating auspicious dates for marriages — both those in which the bride is brought home and those in which she is sent out; calculating auspicious dates for betrothals and divorces; for collecting debts or making investments and loans; reciting charms to make people attractive or unattractive; curing women who have undergone miscarriages or abortions; reciting spells to bind a man's tongue, to paralyze his jaws, to make him lose control over his hands, or to bring on deafness; getting oracular answers to questions addressed to a spirit in a mirror, in a young girl, or to a spirit medium; worshipping the sun, worshipping the Great Brahmā, bringing forth flames from the mouth, invoking the goddess of luck — he abstains from wrong livelihood, from "animal" arts such as these.
"Whereas some contemplatives & brahmans, living off food given in faith, maintain themselves by wrong livelihood, by such "animal" arts as: promising gifts to deities in return for favors; fulfilling such promises; demonology; reciting spells in earth houses [see earth skills, above]; inducing virility and impotence; preparing sites for construction; consecrating sites for construction; giving ceremonial mouthwashes and ceremonial baths; offering sacrificial fires; administering emetics, purges, purges from above, purges from below, head-purges; ear-oil, eye-drops, treatments through the nose, ointments, and counter-ointments; practicing eye-surgery [or: extractive surgery], general surgery, pediatrics; administering root-medicines and binding medicinal herbs — he abstains from wrong livelihood, from "animal" arts such as these. This, too, is part of his virtue."
"A monk thus consummate in virtue sees no danger anywhere from his restraint through virtue. Just as a head-anointed noble warrior king who has defeated his enemies sees no danger anywhere from his enemies, in the same way the monk thus consummate in virtue sees no danger anywhere from his restraint through virtue. Endowed with this noble aggregate of virtue, he is inwardly sensitive to the pleasure of being blameless. This is how a monk is consummate in virtue.
Growing up in a conservative family, I saw my community elders choose a good day for events or celebrations.
That's a good habit and a son would have actually the duty to uphold the families traditions if not harmful ones. Also the Buddha and his faithful disciples practice such and Dates play an important rule. Even such as cutting hairs, travel and times for undertakings... are touched and defined for monks. Many things in this regard had been adopted by laypeople voluntary.
The Buddha focused on the so called Upoastha-days as "the only important" community days all 14 days, allowed (urged) his monks to learn the calculation and many rules are in regard of those days. He also allowed to gather and to teach the Dhamma to the lay-people, after the request of a King who feared that other sects, who hold assemblies for lay people might gain to much popularity while the Buddhas union might lose. Since the day of cleansing is a good and helpful way also for lay people, it's usual to keep the Sila-days as well, all moon-quarters and some practice the "ascetic" days even on more days: pakati-uposatha, pati-jagara-uposatha, pati-harika-pakkha-uposatha.
Pujas (occasions of scarifies) are celebrated on special full-moon days.
In lands with much Dhamma influence new-moon is generally thought as a day before birth i.e. to start something new. Other special days of certain scarifies are found often related to occasions in the past around the Buddha, Dhamma, Sangha.
The have been Arahats at the time of the Buddha who thought "Whether I keep the Uposatha or not, I am clean anyway" and the Buddha encouraged "Who, if not you, would venerate and uphold the Uposatha-day".
Generally, every day is worthy to uphold the Uposatha and it should not be wrong taken, be ill-gotten.
If serious more interested, having the needed freedom, one should not hesitate to use possible more proper, and therefore given environment.
(note: it's not given for trade, exchange, stacks or entertainments binding to world and it's ways, but as a tiny door to escape)
The things (Sankatha) you see are all products of either collective thoughts or the thoughts of an individual.
At that period, Vasettha, there was just one mass of water, and all was darkness, blinding darkness. Neither moon nor sun appeared, no constellations or stars appeared, night and day were not distinguished, nor months and fortnights, no years or seasons, and no male and female, beings being reckoned just as beings. And sooner or later, after a very long period of time, savoury earth spread itself over the waters where those beings were. It looked just like the skin that forms itself over hot milk as it cools. It was endowed with colour, smell and taste. It was the colour of fine ghee or butter, and it was very sweet, like pure wild honey. http://www.columbia.edu/itc/religion/f2001/edit/docs/aggannasutta.pdf
The above is how the Sakwala (the solar system) we belong came into being. The planets, the moon and the sun are all products of living beings. The collective thoughts of all living beings shape the universe.
All beings emit an aura. The pure white is produced by those who do not have Raga, Dosa or Moha. The ones who have emit an aura in a colour spectrum.
The difference in energy is that makes things spin. Everything, the world, the planets and even molecules spin and rotate. This is why things deteriorate.
Over time people become decadent and excessive with money and no sense of responsibility. This increase the spin and bring an end of Kalpa or a complete overhaul of the planet.
There is an element of truth in things like horoscopes. The vibes you emit get stored in the planets and reflects back on you magnified many times over. This is why people have good and bad times.
What the Buddha said was do not worry about planets or the effects but worry about taking away the causes. The causes are Raga, Dosa and Moha.
