The Satya Yuga (a.k.a. Krita Yuga), in Hinduism, is the first and best of the four yugas (world ages) in a Yuga Cycle, preceded by Kali Yuga of the previous cycle and followed by Treta Yuga. Satya Yuga lasts for 1,728,000 years (4,800 divine years).
Satya Yuga is known as the age of truth, when humanity is governed by gods, and every manifestation or work is close to the purest ideal and humanity will allow intrinsic goodness to rule supreme. It is sometimes referred to as the "Golden Age". The god Dharma (depicted in the form of a bull), which symbolizes morality, stood on all four legs during this period. The legs of Dharma reduce by one in each yuga that follows.
Yuga (Sanskrit: युग), in this context, means "an age of the world", where its archaic spelling is yug, with other forms of yugam, yugānāṃ, and yuge, derived from yuj (Sanskrit: युज्, lit. 'to join or yoke'), believed derived from *yeug- (Proto-Indo-European: lit. 'to join or unite').
Satya Yuga (Sanskrit: सत्ययुग, romanized: satyayuga or satya-yuga) means "the age of truth or sincerity", sometimes abbreviated as Sat Yuga or Satyuga.
Krita Yuga (Sanskrit: कृतयुग, romanized: kṛtayuga, kritayuga, kṛta-yuga, or krita-yuga), a synonym for Satya Yuga, means "the accomplished or completed age" or "the age of righteous or action", a time when people perform pious (righteous) actions, and is sometimes referred to as the "Golden Age".
Krita Yuga is described in the Mahabharata, Manusmriti, Surya Siddhanta, Vishnu Smriti, and various Puranas.
Hindu texts describe four yugas (world ages) in a Yuga Cycle, where, starting in order from the first age of Krita (Satya) Yuga, each yuga's length decreases by one-fourth (25%), giving proportions of 4:3:2:1. Each yuga is described as having a main period (a.k.a. yuga proper) preceded by its yuga-sandhyā (dawn) and followed by its yuga-sandhyāṃśa (dusk), where each twilight (dawn/dusk) lasts for one-tenth (10%) of its main period. Lengths are given in divine years (years of the gods), each lasting for 360 solar (human) years.
Krita Yuga, the first age in a cycle, lasts for 1,728,000 years (4,800 divine years), where its main period lasts for 1,440,000 years (4,000 divine years) and its two twilights each lasts for 144,000 years (400 divine years). The current cycle's Krita Yuga has the following dates based on Kali Yuga, the fourth and present age, starting in 3102 BCE:
|Part||Start (– End)||Length|
|Krita-yuga-sandhya (dawn)||3,891,102 BCE||144,000 (400)|
|Krita-yuga (proper)||3,747,102 BCE||1,440,000 (4,000)|
|Krita-yuga-sandhyamsa (dusk)||2,307,102 BCE – 2,163,102 BCE||144,000 (400)|
|Years: 1,728,000 solar (4,800 divine)|
|Current: Kali-yuga-sandhya (dawn).|||
Mahabharata, Book 12 (Shanti Parva), Ch. 231:[a]
(17) A year (of men) is equal to a day and night of the gods ... (19) I shall, in their order, tell you the number of years that are for different purposes calculated differently, in the Krita, the Treta, the Dwapara, and the Kali yugas. (20) Four thousand celestial years is the duration of the first or Krita age. The morning of that cycle consists of four hundred years and its evening is of four hundred years. (21) Regarding the other cycles, the duration of each gradually decreases by a quarter in respect of both the principal period with the minor portion and the conjoining portion itself.
Manusmriti, Ch. 1:
(67) A year is a day and a night of the gods ... (68) But hear now the brief (description of) the duration of a night and a day of Brahman and of the several ages (of the world, yuga) according to their order. (69) They declare that the Krita age (consists of) four thousand years (of the gods); the twilight preceding it consists of as many hundreds, and the twilight following it of the same number. (70) In the other three ages with their twilights preceding and following, the thousands and hundreds are diminished by one (in each).
Surya Siddhanta, Ch. 1:
(13) ... twelve months make a year. This is called a day of the gods. (14) ... Six times sixty  of them are a year of the gods ... (15) Twelve thousand of these divine years are denominated a Quadruple Age (caturyuga); of ten thousand times four hundred and thirty-two [4,320,000] solar years (16) Is composed that Quadruple Age, with its dawn and twilight. The difference of the Golden and the other Ages, as measured by the difference in the number of the feet of Virtue in each, is as follows : (17) The tenth part of an Age, multiplied successively by four, three, two, and one, gives the length of the Golden and the other Ages, in order : the sixth part of each belongs to its dawn and twilight.
The Mahabharata, a Hindu epic, describes Krita Yuga as such:
there were no poor and no rich; there was no need to labor, because all that men required was obtained by the power of will; the chief virtue was the abandonment of all worldly desires. The Krita Yuga was without disease; there was no lessening with the years; there was no hatred or vanity, or evil thought; no sorrow, no fear. All mankind could attain to supreme blessedness.
Among the four eras, the Satya Yuga is the first and the most significant one. Knowledge, meditation, and penance hold special importance in this era. All the pillars of dharma are present in totality. During Satya Yuga, all people engage only in good, sublime deeds. Ashrams become devoid of wickedness and deceit. Natyam (classical dance), according to Natya Shastra, did not exist in the Satya Yuga "because it was the time when all people were happy". Lord Vishnu incarnated in four forms i.e. Matsya, Kurma, Varaha and Narsimha in this era. The only text which was considered credible and was followed was Manu’s Dharma Shastra. The average human lifespan in Satya Yuga began with 100,000 years and gradually decreased to 10,000 years.
One shall witness the total establishment of Sanatan Dharma (eternal religion). All the deities, demons, Gandharvas, and Yaksha would give up their hatred and differences. The Rigveda, Samaveda and Yajurveda were not separate and demarcated. This era was devoid of agricultural activities or any other type of activity. Just by mere contemplation one would beget desired results. People in this era would never fall ill. No one would try to point out faults or demerits in anyone’s personality. The personality was not plagued by demerits like ego, sorrow, violent thought (aggression), jealousy, hatred, backbiting, fear, anger and lethargy.
At that time, the color of the Supreme cosmic soul that was situated in the heart of one and all and the savior of all the sages was white (light).
All the people that are Brahmins, Kshatriyas, Vaishyas and Shudras were embellished with all the good qualities. People would practice austerities and penance to attain Brahman. All would be inclined towards the supreme knowledge and all actions performed would be in the intention of attaining celestial bliss.
In this way all these divine people would be bestowed with sublime faith and piousness. Albeit, people were segregated on the basis of the varnashram method, they would all response their faith in the Vedas and the Sanatan Dharma because these people were devoid of selfishness, and they would effortlessly attain sublimity or union with God, which is a salient feature of Satya Yuga. Very valiant, mighty, intelligent and people gifted with all good qualities would be born in this era. They would surprisingly give birth to thousands of children. Great sages embellished with divinity would be born in this era.
* HINDUISM: Myths of time and eternity: ... Each yuga is preceded by an intermediate "dawn" and "dusk." The Krita yuga lasts 4,000 god-years, with a dawn and dusk of 400 god-years each, or a total of 4,800 god-years; Treta a total of 3,600 god-years; Dvapara 2,400 god-years; and Kali (the current yuga) 1,200 god-years. A mahayuga thus lasts 12,000 god-years ... Since each god-year lasts 360 human years, a mahayuga is 4,320,000 years long in human time. Two thousand mahayugas form one kalpa (eon) [and pralaya], which is itself but one day in the life of Brahma, whose full life lasts 100 years; the present is the midpoint of his life. Each kalpa is followed by an equally long period of abeyance (pralaya), in which the universe is asleep. Seemingly the universe will come to an end at the end of Brahma's life, but Brahmas too are innumerable, and a new universe is reborn with each new Brahma.
* YUGA: Each yuga is progressively shorter than the preceding one, corresponding to a decline in the moral and physical state of humanity. Four such yugas (called ... after throws of an Indian game of dice) make up a mahayuga ("great yuga") ... The first yuga (Krita) was an age of perfection, lasting 1,728,000 years. The fourth and most degenerate yuga (Kali) began in 3102 BCE and will last 432,000 years. At the close of the Kali yuga, the world will be destroyed by fire and flood, to be re-created as the cycle resumes. In a partially competing vision of time, Vishnu's 10th and final AVATAR, KALKI, is described as bringing the present cosmic cycle to a close by destroying the evil forces that rule the Kali yuga and ushering in an immediate return to the idyllic Krita yuga.
Paraphrased: Deva day equals solar year. Deva lifespan (36,000 solar years) equals 100 360-day years, each 12 months. Mahayuga equals 12,000 Deva (divine) years (4,320,000 solar years), and is divided into 10 charnas consisting of four Yugas: Satya Yuga (4 charnas of 1,728,000 solar years), Treta Yuga (3 charnas of 1,296,000 solar years), Dvapara Yuga (2 charnas of 864,000 solar years), and Kali Yuga (1 charna of 432,000 solar years). Manvantara equals 71 Mahayugas (306,720,000 solar years). Kalpa (day of Brahma) equals an Adi Sandhya, 14 Manvantaras, and 14 Sandhya Kalas, where 1st Manvantara preceded by Adi Sandhya and each Manvantara followed by Sandhya Kala, each Sandhya lasting same duration as Satya yuga (1,728,000 solar years), during which the entire earth is submerged in water. Day of Brahma equals 1,000 Mahayugas, the same length for a night of Brahma (Bhagavad-gita 8.17). Brahma lifespan (311.04 trillion solar years) equals 100 360-day years, each 12 months. Parardha is 50 Brahma years and we are in the 2nd half of his life. After 100 years of Brahma, the universe starts with a new Brahma. We are currently in the 28th Kali yuga of the first day of the 51st year of the second Parardha in the reign of the 7th (Vaivasvata) Manu. This is the 51st year of the present Brahma and so about 155 trillion years have elapsed. The current Kali Yuga (Iron Age) began at midnight on 17/18 February 3102 BC in the proleptic Julian calendar.