Hindu units of time are described in Hindu texts ranging from microseconds to trillions of years, including cycles of cosmic time that repeat general events in Hindu cosmology.[1] [2] Time () is described as eternal. Various fragments of time are described in the Vedas, Manusmriti, Bhagavata Purana, Vishnu Purana, Mahabharata, Surya Siddhanta etc.[3] [4] [5]
See also: Sidereal and tropical astrology and Sidereal time.
Sidereal astrology maintains the alignment between signs and constellations via corrective systems of Hindu (Vedic)-origin known as ayanamsas (Sanskrit:
Ayanamsa systems used in Hindu astrology (also known as Vedic astrology) include the Lahiriayanamsa and the Raman ayanamsa.[8] The Fagan-Bradley ayanamsa is an example of an ayanamsa system used in Western sidereal astrology. As of 2020, zodiacal signs calculated using the Sri Yukteswar ayanamsa were around 23 degrees behind tropical zodiacal signs. Per these calculations, persons born between March 12 - April 12, for instance, would have the sun sign of Pisces. By contrast, persons born between March 21 - April 19 would have the sun sign of Aries per tropical calculations.[9]
Sidereal Units:
| Unit | Definition | Value in SI units |
|---|---|---|
| truti (Sanskrit: त्रुटि) | base unit | ≈ 300 ns |
| renu (Sanskrit: रेणु) | 60 truti | ≈ 18 μs |
| lava (Sanskrit: लव) | 60 renu | ≈ 1,080 μs |
| (Sanskrit: लीक्षक) | 60 lava | ≈ 64.8 ms |
| (Sanskrit: लिप्ता) | 6 | ≈ 0.3888 s |
| vipala (Sanskrit: विपल) | ||
| [10] (Sanskrit: प्राण) | 10 | ≈ 3.888 s |
| pala (Sanskrit: पल) | 60 or 6 | ≈ 24 s |
| (Sanskrit: विघटि) | ||
| (Sanskrit: विनाडी) | ||
| (Sanskrit: घटि) | 60 | ≈ 1.44 ks (24 min) |
| (Sanskrit: नाडी) | ||
| danda (Sanskrit: दण्ड) | ||
| (Sanskrit: मुहूर्त) | 2 | ≈ 2.88 ks (48 min) |
(sidereal day; Sanskrit: नक्षत्र अहोरात्रम्) | 60 | ≈ 86.4 ks (24 h) |
| 30 |
According to :[11]
| Unit | Definition | Value in SI units | |
|---|---|---|---|
| truti | base unit | ≈ 29.6 μs | |
| tatpara | 100 truti | ≈ 2.96 ms | |
| nimesha | 30 tatpara | ≈ 88.9 ms | |
| 18 nimesha | ≈ 1.6 s | ||
| 30 | ≈ 48 s | ||
| ghatika | 30 | ≈ 1.44 ks (24 min) | |
| 2 ghatika | ≈ 2.88 ks (48 min) | ||
(sidereal day) | 30 | ≈ 86.4 ks (24 h) |
Small units of time used in the Vedas:
| Unit | Definition | Value in SI units |
|---|---|---|
| base unit | ≈ 26.3 μs | |
| 2 | ≈ 52.67 μs | |
| 3 | ≈ 158 μs | |
| 3 | ≈ 474 μs | |
| vedha | 100 | ≈ 47.4 ms |
| lava | 3 vedha | ≈ 0.14 s |
| 3 lava | ≈ 0.43 s | |
| 3 | ≈ 1.28 s | |
| 5 | ≈ 6.4 s | |
| laghu | 15 | ≈ 96 s (1.6 min) |
| danda (nadika) | 15 laghu | ≈ 1.44 ks (24 min) |
| 2 danda | ≈ 2.88 ks (48 min) | |
(sidereal day) | 30 | ≈ 86.4 ks (24 h) |
| masa (month) | 30 | ≈ 2,592 ks |
| ritu (season) | 2 masa | ≈ 5,184 ks |
| ayana | 3 ritu | ≈ 15,552 ks (6 mth) |
| samvatsara (year) | 2 ayana | ≈ 31,104 ks |
| of Deva |
See also: Lunar distance (astronomy), Orbit of the Moon, Ephemeris and Astronomical basis of the Hindu calendar.
The traditional lunar calendar system measures time based on the Moon's phases and its relation to the Sun. Unlike solar calendars, it uses units such as tithi (lunar day), pakṣa (lunar fortnight), māsa (lunar month), ṛitu (season), ayanam (half-year), and varsha (lunar year) to structure the year.[12] This system was integral to ancient cultures for tracking time, planning festivals, and guiding agricultural practices. The following section provides an overview of these key time units and their relationships:[13]
| Unit | Definition | Equivalence | |
|---|---|---|---|
| tithi (lunar day) | Time for 12° increase of longitudinal angle between Moon and Sun | ≈ 1 day (varies 19–26 hours) | |
| (lunar fortnight) | 15 tithis | ≈ 15 days | |
| (lunar month) | 2 : gaura (bright) or during waxing moon; (dark) during waning moon | ≈ 30 days (29.5 days) | |
| (season) | 2 | ≈ 60 days | |
| ayanam | 3 | ≈ 180 days | |
| varsha (lunar year) | 2 ayanams | ≈ 360 days (354.36707 days) |
See also: Tropical year.
Tropical metrics are time units used to measure intervals based on the tropical year and related cycles. This system includes units such as ghaṭi (base unit), yāma (a period of 7.5 ghaṭis), and ahorātram (a full day comprising 8 yāmas).[14] The following section explains these units and their approximate durations, offering insight into how time is organized in relation to the tropical year:
| Unit | Definition | Equivalence | |
|---|---|---|---|
| (Sanskrit: घटि) | base unit | ≈ 24 minutes | |
| (Sanskrit: याम) | 7.5 | ≈ 3 hours | |
| (Sanskrit: अहोरात्रम्) | 8 | ≈ 24 hours (tropical day starting at sunrise) |
The table below contains calculations of cosmic Hindu units of time as experienced by different entities, namely humans, Pitris (forefathers), Devas (gods), Manu (progenitor of humanity), and Brahma (creator god). Calculations use a traditional 360-day year (twelve 30-day months) and a standard 24-hour day for all entities.
| Definition | Human | Pitri | Deva | Manu | Brahma | ||
|---|---|---|---|---|---|---|---|
| 36,000 kalpa & pralaya | 311,040,000,000,000 yr | 10,368,000,000,000 yr | 864,000,000,000 yr | ~ | 100 yr | ||
| length | |||||||
| 155,520,000,000,000 yr | 5,184,000,000,000 yr | 432,000,000,000 yr | ~ | 50 yr | |||
| kalpa | 14 m + 15 ms; 1,000 cy | 4,320,000,000 yr | 144,000,000 yr | 12,000,000 yr | ~ | 12 h | |
| pralaya | kalpa length | ||||||
| manvantara [m] | 71 | 306,720,000 yr | 10,224,000 yr | 852,000 yr | 100 yr | ||
| [ms] | length | 1,728,000 yr | 57,600 yr | 4,800 yr | ~ | 17.28 s | |
| [cy] | ,, & Kali-yugas | 4,320,000 yr | 144,000 yr | 12,000 yr | ~ | 43.20 s | |
| sum total | 1,728,000 yr | 57,600 yr | 4,800 yr | ~ | 17.28 s | ||
| length | 144,000 yr | 4,800 yr | 400 yr | ~ | 1.44 s | ||
| 4 Kali-yuga lengths | 1,440,000 yr | 48,000 yr | 4,000 yr | ~ | 14.40 s | ||
| sum total | 1,296,000 yr | 43,200 yr | 3,600 yr | ~ | 12.96 s | ||
| length | 108,000 yr | 3,600 yr | 300 yr | ~ | 1.08 s | ||
| 3 Kali-yuga lengths | 1,080,000 yr | 36,000 yr | 3,000 yr | ~ | 10.80 s | ||
| sum total | 864,000 yr | 28,800 yr | 2,400 yr | ~ | 8.64 s | ||
| length | 72,000 yr | 2,400 yr | 200 yr | ~ | 0.72 s | ||
| 2 Kali-yuga lengths | 720,000 yr | 24,000 yr | 2,000 yr | ~ | 7.20 s | ||
| Kali-yuga | sum total | 432,000 yr | 14,400 yr | 1,200 yr | ~ | 4.32 s | |
| Kali-yuga length | 36,000 yr | 1,200 yr | 100 yr | ~ | 0.36 s | ||
| Kali-yuga | 1,000 Deva years | 360,000 yr | 12,000 yr | 1,000 yr | ~ | 3.60 s | |
Hindu texts define lifespans differently for humans, Pitris (forefathers), Devas (gods), Manus (progenitors of mankind), and Brahma (creator god). The division of a year for each is twelve 30-day months or 360 days, where a day is divided into a 12-hour day proper and 12-hour night.[15] A 30-day month amounts to four 7-day weeks with an extra 8th day every two weeks (48-week year). A traditional human year is measured by the sun's northern (uttarayana) and southern (dakshinayana) movements in the sky, where the new year commences only when the sun returns to the same starting point and a pause on the commencement otherwise. Ebenezer Burgess postulates an intercalary month was inserted every five years to anciently maintain the correspondence of the 360-day years with the true solar years (~365.24-day years). For this reason, a traditional 360-day year is equivalent to a modern ~365.24-day solar or tropical year.
| Human | Pitri | Deva | Manu | Brahma | ||
|---|---|---|---|---|---|---|
| Brahma year | 3,110,400,000,000 yr | 103,680,000,000 yr | 8,640,000,000 yr | ~ | 1 yr | |
| Manu year | 3,067,200 yr | 102,240 yr | 8,520 yr | 1 yr | ||
| Deva year | 360 yr | 12 yr | 1 yr | ~ | ||
| Pitri year | 30 yr | 1 yr | ~ | |||
| Human year | 1 yr | ~ |
According to Puranic sources, Krishna's departure marks the end of the human age of Dvapara-yuga and the start of Kali-yuga, which is dated to midnight on 17/18 February 3102BCE of the proleptic Julian calendar. We are currently halfway through Brahma's life (maha-kalpa), whose lifespan is equal to the duration of the manifested material elements, from which Brahma manifests his universe in kalpa cycles:[16] [17]
A maha-kalpa is followed by a maha-pralaya (full dissolution) of equal length. Each kalpa (day of Brahma) is followed by a pralaya (night of Brahma or partial dissolution) of equal length. Preceding the first and following each manvantara is a manvantara-sandhya (connection period), each with a length of Krita-yuga (Satya-yuga).
Hindu texts specify that the start and end of each of the yugas are marked by astronomical alignments. This cycle's Treta-yuga began with 5 planets residing in the "Aries" constellation. This cycle's Dvapara-yuga ended with the "Saptarshi" constellation (Ursa major) residing in the "Magha" constellation. The current Kali-yuga will end with the Sun, Moon and Jupiter residing in the "Pushya" sector.[18]
See main article: Yuga Cycle.
The history of humanity is divided up into four yugas (dharmic ages or world ages)— (pronounced Krita-yuga; Satya-yuga), , and Kali-yuga—each with a 25% decline in dharmic practices and length, giving proportions (; pronounced charanas) of 4:3:2:1 (e.g. Satya: 100% start; Kali: 25% start, 0% end), indicating a de-evolution in spiritual consciousness and an evolution in material consciousness. Kali-yuga is followed by Satya-yuga of the next cycle, where a cycle is called a (pronounced chatur-yuga; mahā-yuga). Each yuga is divided into a main period (yuga proper) and two yuga-sandhis (; connecting periods)— (dawn) and (; dusk)—where each yuga-sandhi lasts for 10% of the main period. Lengths are given in divine years (celestial or Deva years), where a divine year lasts for 360 solar (human) years. A chatur-yuga lasts for 4.32 million solar (12,000 divine) years with 1,728,000 years of Krita-yuga, 1,296,000 years of Treta-yuga, 864,000 years of Dvapara-yuga, and 432,000 years of Kali-yuga.[19] [20] [21] [22]
Kali-yuga lasts for 432,000 years and is the 4th of 4 yugas in a cycle as well as the current yuga, with two sandhyas, each lasting for 36,000 years:
= current year + Kali-yuga start year - year zero
= + 3102 - 1
= years
= Kali-yuga-sandhya - elapsed Kali-yuga
= 36,000 - (+ 3102 - 1)
= years
= Kali-yuga - Kali-yuga-sandhyamsa - elapsed Kali-yuga
= 432,000 - 36,000 - (+ 3102 - 1)
= years
= Kali-yuga - elapsed Kali-yuga
= 432,000 - (+ 3102 - 1)
= years
A chatur-yuga lasts for 4.32million years, where the current is the 28th of 71:
= chatur-yuga - Kali-yuga + elapsed Kali-yuga
= 4,320,000 - 432,000 + (+ 3102 - 1)
= years
≈ million years
= Kali-yuga - elapsed Kali-yuga
= 432,000 - (+ 3102 - 1)
= years
| Yuga | Start (– End) | Length | |
|---|---|---|---|
| Krita (Satya) | 3,891,102BCE | 1,728,000 (4,800) | |
| Treta | 2,163,102BCE | 1,296,000 (3,600) | |
| Dvapara | 867,102BCE | 864,000 (2,400) | |
| Kali | 3102BCE428,899CE | 432,000 (1,200) | |
| Years: 4,320,000 solar (12,000 divine) | |||
The lifespan of the Pitris (forefathers) lasts for 100 of their years.
The lifespan of the Devas (gods) lasts for 100 of their years.
See main article: Manvantara.
The lifespan of the Manus (progenitors of mankind) lasts for 100 of their years. Each Manu reigns over a period called a manvantara, each lasting for 71 chatur-yugas (306.72 million years). A total of 14 Manus reign successively in one kalpa (day of Brahma). Preceding the first and following each manvantara is a (connection period), each lasting the duration of Satya-yuga (1.728 million years). During each (manvantara-sandhi), Earth (Bhu-loka) is submerged in water.[23] [24] [25]
A manvantara lasts for 306.72million years, where the current (ruled by Vaivasvatha Manu) is the 7th of 14:
= elapsed 28th chatur-yuga + 27 chatur-yugas
= chatur-yuga - Kali-yuga + elapsed Kali-yuga + 27 chatur-yugas
= (4,320,000 - 432,000 + (+ 3102 - 1)) + 4,320,000 * 27
= years
≈ million years
= remaining 28th chatur-yuga + 43 chatur-yugas
= Kali-yuga - elapsed Kali-yuga + 43 chatur-yugas
= (432,000 - (+ 3102 - 1)) + 4,320,000 * 43
= years
≈ million years
See main article: Kalpa (time).
The lifespan of Brahma (creator god) lasts for 100 of his years. His 12-hour day or kalpa (day of Brahma) is followed by a 12-hour night or pralaya (night of Brahma) of equal length, each lasting for 4.32 billion years. A kalpa lasts for 1,000 chatur-yugas and has 14 manvantaras and 15 manvantara-sandhyas occurring in it. At the start of Brahma's days, he is re-born and creates the planets and the first living entities. At the end of his days, he and his creations are unmanifest (partial dissolution). His 100-year life (311.04 trillion years) is called a, which is followed by a (full dissolution) of equal length, where the bases of the universe, prakriti, is manifest at the start and unmanifest at the end of a maha-kalpa. His 100-year life is divided into two 50-year periods, each called a .[25] [26] In 100 360-day years (maha-kalpa), there are a total of 36,000 full days: 36,000 kalpas (days proper) and 36,000 pralayas (nights).
A kalpa (day of Brahma, 12 hours) lasts for 4.32billion years, where the current (Shveta-Varaha Kalpa) is the 1st of 30 in his 1st month of his 51st year:
= elapsed 7th manvantara + 7 manvantara-sandhyas + 6 manvantaras
= elapsed 28th chatur-yuga + 27 chatur-yugas + 7 manvantara-sandhyas + 6 manvantaras
= chatur-yuga - Kali-yuga + elapsed Kali-yuga + 27 chatur-yugas + 7 manvantara-sandhyas + 6 manvantaras
= ((4,320,000 - 432,000 + (+ 3102 - 1)) + 4,320,000 * 27) + 1,728,000 * 7 + 306,720,000 * 6
= years
≈ billion years
= remaining 7th manvantara + 8 manvantara-sandhyas + 7 manvantaras
= remaining 28th chatur-yuga + 43 chatur-yugas + 8 manvantara-sandhyas + 7 manvantaras
= Kali-yuga - elapsed Kali-yuga + 43 chatur-yugas + 8 manvantara-sandhyas + 7 manvantaras
= ((432,000 - (+ 3102 - 1)) + 4,320,000 * 43) + 1,728,000 * 8 + 306,720,000 * 7
= years
≈ billion years
A maha-kalpa (life of Brahma) lasts for 311.04trillion years:
= elapsed 18,001st kalpa + 18,000 kalpas + 18,000 pralayas
= elapsed 7th manvantara + 7 manvantara-sandhyas + 6 manvantaras + 36,000 kalpas/pralayas
= elapsed 28th chatur-yuga + 27 chatur-yugas + 7 manvantara-sandhyas + 6 manvantaras + 36,000 kalpas/pralayas
= chatur-yuga - Kali-yuga + elapsed Kali-yuga + 27 chatur-yugas + 7 manvantara-sandhyas + 6 manvantaras + 36,000 kalpas/pralayas
= (((4,320,000 - 432,000 + (+ 3102 - 1)) + 4,320,000 * 27) + 1,728,000 * 7 + 306,720,000 * 6) + 4,320,000,000 * 36,000
= years
≈ trillion years
= remaining 18,001st kalpa + 17,999 kalpas + 18,000 pralayas
= remaining 7th manvantara + 8 manvantara-sandhyas + 7 manvantaras + 35,999 kalpas/pralayas
= remaining 28th chatur-yuga + 43 chatur-yugas + 8 manvantara-sandhyas + 7 manvantaras + 35,999 kalpas/pralayas
= Kali-yuga - elapsed Kali-yuga + 43 chatur-yugas + 8 manvantara-sandhyas + 7 manvantaras + 35,999 kalpas/pralayas
= (((432,000 - (+ 3102 - 1)) + 4,320,000 * 43) + 1,728,000 * 8 + 306,720,000 * 7) + 4,320,000,000 * 35,999
= years
≈ trillion years
The Mahabharata (12.231.12–31) describes units of time from a wink of the eye (nimesha) up to the days (kalpa) and nights (pralaya) of Brahma.
The Manusmriti (Laws of Manu; 1.64–80) describes units of time from a twinkling of the eye (nimesha) up to the days (kalpa) and nights (pralaya) of Brahma.[27] [28]
According to Patrick Olivelle, most scholars take the table of contents (1.111–118) to be an addition, but for him the account of time and cosmology (1.61–86) to the aforementioned (1.118) are out of place redactions. He feels the narrative should have ended when the initial command to "listen" (1.4) was repeated (1.60), then transition to "learn" (2.1).
Georg Bühler, whose translation has remained the standard for over a century according to Olivelle, translated 1.71 as 12,000 years in a four-aged period, same as Sir William Jones's translation, both based on Kulluka Bhatta's commentary. Medhatithi translated it as 12,000 four-aged periods in an age of the gods. Kulluka and Olivelle reject Medhatithi's interpretation based on 1.79 mentioning 12,000 without a qualifier ("etat" or "this") and must be assumed as years.[29]
The Surya Siddhanta (1.10–21) describes units of time from a respiration (prana) up to the 100-year lifespan of Brahma (maha-kalpa).