Friday, January 1, 2016

Hindu units of time

Vedic and Puranic texts describe units of Kala measurements, from Paramaṇu (about 17 microseconds) to Maha-Manvantara (311.04 trillion years). According to these texts, the creation and destruction of the universe is a cyclic process, which repeats itself forever. Each cycle starts with the birth and expansion (lifetime) of the universe equaling 311.04 trillion years, followed by its complete annihilation (which also prevails for the same duration). The current Universe was created in Padma kalpa, the last day Kalpa of 50th year of Brahma. This is 10.51 billion years ago. This figure is close to the modern estimated age of the universe in ≈ 13.79 billion years.
Various units of time are used across the Vedas, Puranas, Mahabharata, Suryasidhanta etc. Especially, Nimesha's multiple, it varies to 3, 10, 15, 18, 20, 27, 30, 45, 48, 60. At the lower end, these are pretty consistent. The Complete Hindu metrics of time (Kāla Vyavahāra) can be summarised as below.
UnitDefinitionEquivalence (Approx.)
Trutiत्रुटि0.031 µs
Renuरेणु60 Truti1.86 µs
Lavaलव60 Renu0.11 ms
Līkṣakaलीक्षक60 Lava6.696 ms
Liptaलिप्ता60 Leekshaka0.401 s
Vipalaविपल
Palaपल60 Lipta24.1056 s
Vighaṭiविघटि
Vinādīविनाडी
Ghaṭiघटि60 Vighaṭi24 min
Nādīनाडी
Dandaदण्ड
Muhūrtaमुहूर्त2 Ghaṭi48 min
Nakṣatra Ahorātram (Sidereal Day)नक्षत्र अहोरात्रम्60 Ghaṭī24 h
30 Muhūrta24 h
Alternate system
UnitDefinitionEquivalence (Approx.)
Truti35.5 µs
Tatpara100 Truti3.55 ms
Nimesha30 Tatpara106.7 ms
Kāṣṭhā30 Nimesha3.2 s
Kalā30 Kāṣṭhā1.6 min
Muhūrta30 Kalā48 min
Nakṣatra Ahorātram (Sidereal Day)30 Muhūrta24 h

Small units of time used in the Vedas

UnitDefinitionEquivalence (Approx.)
Paramāṇu26.3 µs
Aṇu2 Paramāṇu57.7 µs
Trasareṇu3 Aṇu158 µs
Truṭi3 Trasareṇu474 µs
Vedha100 Truṭi47.4 ms
Lava3 Vedha0.14 s
Nimeṣa3 Lava0.43 s
Kṣaṇa3 Nimesha1.28 s
Kāṣṭhā5 Kṣaṇa6.4 s
Laghu15 Kāṣṭhā1.6 min
Danda15 Laghu24 min
Muhūrta2 Danda48 min
Ahorātram (Day)30 Muhūrta24 h
Masa (Month)30 Ahorātram30 days
Ritu (Season)2 Masa2 months
Ayana3 Rutu6 months
Samvatsara (Year)2 Ayana360 days

Lunar metrics
A Tithi or lunar day is defined as the time it takes for the longitudinal angle between the moon and the Sun to increase by 12°.[1] Tithis begin at varying times of day and vary in duration from approximately 19 to approximately 26 hours.
A Paksa (also Pakṣa) or lunar fortnight consists of 15 tithis.
A Māsa or lunar month (approximately 29.5 days) is divided into 2 Pakṣas: the one between new moon and full moon (waxing) is called gaura or (bright) or Śukla Pakṣa; the one between full moon and new moon (waning) Kṛiṣhṇa (dark) paksha
A Ṛitu (or season) is 2 Māsa[2]
An Ayana is 3 Ṛitus
A year is two Ayanas [1][3]
Tropical metrics
A Yāma = 1/4 of a day (light) or night [ = 7½ Ghatis (घटि) = 3¾ Muhurtas = 3 Horas (होरा) ]
Four Yāmas make half of the day (either day or night)
Eight Yāmas make an Ahorātra (day + night)
An Ahorātra is a tropical day (Note: A day is considered to begin and end at sunrise, not midnight.)
NameDefinitionEquivalence
Yamaयाम¼ th of a day (light) or night3 hours
Sāvana Ahorātramसावन अहोरात्रम्8 Yamas1 Solar day
Reckoning of time among other entities.
Among the Pitṛs (forefather) in their Dimension (Loka):
1 human fortnight (15 days) = 1 day (light) or night of the Pitṛs.
1 human month (30 days) = 1 day (light) and night of the Pitṛs.
30 days of the Pitṛs = 1 month of the Pitṛs = (30 × 30 = 900 human days).
12 months of the Pitṛs = 1 year of the Pitṛs = (12 months of Pitṛs × 900 human days = 10800 human days).
The lifespan of the Pitṛs is 100 years of the Pitṛs (= 36,000 Pitṛ days = 1,080,000 human days = 3000 human years)
1 day of the Devas = 1 human year
1 month of the Devas = 30 days of the Devas
1 year of the Devas (1 divine year) = 12 months of the Devas
Among the Devas in their Dimension (Loka):
The life span of any Hindu deva spans nearly (or more than) 4.5 million years. Statistically, we can also look it as:
12000 Deva Years = Life Span of Devas = 1 Mahā-Yuga.
The Viṣṇu Purāṇa Time measurement section of the Viṣṇu Purāṇa Book I Chapter III explains the above as follows:
2 Ayanas (6-month periods, see above) = 1 human year or 1 day of the devas
4,000 + 400 + 400 = 4,800 divine years (= 1,728,000 human years) = 1 Satya Yuga
3,000 + 300 + 300 = 3,600 divine years (= 1,296,000 human years) = 1 Tretā Yuga
2,000 + 200 + 200 = 2,400 divine years (= 864,000 human years) = 1 Dvāpara Yuga
1,000 + 100 + 100 = 1,200 divine years (= 432,000 human years) = 1 Kali Yuga
12,000 divine year = 4 Yugas (= 4,320,000 human years) = 1 Mahā-Yuga (also is equaled to 12000 Daiva (divine) Yuga)
[2*12,000 = 24,000 divine year = 12000 revolutions of sun around its dual]
For Brahma in their Dimension (Loka):
1000 Mahā-Yugas = 1 Kalpa = 1 day (day only) of Brahma
(2 Kalpas constitute a day and night of Brahma, 8.64 billion human years)
30 days of Brahma = 1 month of Brahma (259.2 billion human years)
12 months of Brahma = 1 year of Brahma (3.1104 trillion human years)
50 years of Brahma = 1 Parārdha
2 parardhas = 100 years of Brahma = 1 Para = 1 Mahā-Kalpa (the lifespan of Brahma)(311.04 trillion human years)
One day of Brahma is divided into 1000 parts called charaṇas. The charaṇas are divided as follows:
The Four Yugas
4 charaṇas (1,728,000 solar years)Satya Yuga
3 charaṇas (1,296,000 solar years)Treta Yuga
2 charaṇas (864,000 solar years)Dvapara Yuga
1 charaṇas (432,000 solar years)Kali Yuga
The cycle repeats itself, so altogether there are 1,000 cycles of Mahā-Yuga in one day of Brahma.
  • One cycle of the above four Yugas is one Mahā-Yuga (4.32 million solar years)
  • as is confirmed by the Gītā Śloka 8.17 (statement) "sahasra-yuga-paryantam ahar yad brahmaṇo viduḥ rātriṁ yuga-sahasrāntāṁ te 'ho-rātra-vido janāḥ", meaning, a day of brahma is of 1000 Mahā-Yuga. Thus a day of Brahma, Kalpa, is of duration: 4.32 billion solar years. Two Kalpas constitute a day and night (Adhi Sandhi) of Brahma.
  • Manvantara consists of 71 Mahā-Yuga (306,720,000 solar years). Each Manvantara is ruled by a Manu.
  • After each Manvantara follows one Saṃdhi Kāla of the same duration as a Kṛta Yuga (1,728,000 = 4 Charaṇas). (It is said that during a Saṃdhi Kāla, the entire earth is submerged in water.)
  • Kalpa consists of a period of 4.32 Billion solar years followed by 14 Manvataras and Saṃdhi Kalas.
  • A day of Brahma equals
(14 times 71 Mahā-Yuga) + (15 × 4 Charaṇas)
= 994 Mahā-Yuga + (15 * 4800)
= 994 Mahā-Yuga + (72,000 years)[deva years] / 6 = 12,000[deva years] viz. one maha yuga.
= 994 Mahā-Yuga + 6 Mahā-Yuga
= 1,000 Mahā-Yuga

The Surya Siddhanta definition of timescales

The Surya Siddhanta [Chapter 14 Mānādhyāyah (मानाध्यायः)], documents a comprehensive model of nine divisions of time called māna (मान) which span from very small time units (Prāņa [प्राण] - 4 seconds) to very large time scales (Para [पर] - 311.04 Trillion solar years).