View source for Hindu units of time

{{short description|none}}
{{Use dmy dates|date=December 2016}}
{{Hinduism}}

'''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]].<ref>{{cite book |author-last=Gupta |author-first=S. V. |year=2010 |chapter=Ch. 1.2.4 Time Measurements |editor-last1=Hull |editor-first1=Robert |editor-last2=Osgood |editor-first2=Richard M. Jr. |editor-link2=Richard M. Osgood Jr. |editor-last3=Parisi |editor-first3=Jurgen |editor-last4=Warlimont |editor-first4=Hans |title=Units of Measurement: Past, Present and Future. International System of Units |chapter-url=https://books.google.com/books?id=pHiKycrLmEQC&pg=PA7 |series=Springer Series in Materials Science: 122 |publisher=[[Springer Publishing|Springer]] |page=3 |isbn=9783642007378}}</ref><ref>{{cite book |title=Lost Discoveries: The Ancient Roots of Modern Science—from the Babylonians to the Maya |author=Dick Teresi |page=174 |publisher=Simon & Schuster}}</ref> Time ([[Kaal|{{IAST|kāla}}]]) is described as eternal.{{sfn|Gupta|2010|p=8}} Various fragments of time are described in the [[Vedas]], ''[[Manusmriti]]'', ''[[Bhagavata Purana]]'', ''[[Vishnu Purana]]'', ''[[Mahabharata]]'', ''[[Surya Siddhanta]]'' etc.<ref>{{Cite web|title=Time – Vyasa Mahabharata|url=https://www.vyasaonline.com/encyclopedia/time/|access-date=2021-12-31|language=en-US}}</ref><ref>{{Cite book|last1=Gupta|first1=Ravi|url=https://books.google.com/books?id=-1WrAgAAQBAJ&dq=time+in+bhagavata+purana&pg=PA277|title=The Bhagavata Purana: Sacred Text and Living Tradition|last2=Valpey|first2=Kenneth|date=2013-03-26|publisher=Columbia University Press|isbn=978-0-231-14999-0|language=en}}</ref><ref>{{Cite web|date=2015-02-01|title=Concept and Measurement of Time in the Vedas|url=https://www.sanskritimagazine.com/concept-measurement-time-vedas/|access-date=2021-12-31|website=Sanskriti|language=en-US}}</ref>

==Sidereal metrics==
{{see also | Sidereal and tropical astrology | Sidereal time }}
[[Image:HinduMeasurements.svg|thumb|200px|Hindu measurements in [[logarithm]]ic scale based on seconds]]

Sidereal astrology maintains the alignment between signs and [[constellation]]s via corrective systems of [[Hindu]] ([[Vedas|Vedic]])-origin known as [[ayanamsa]]s (Sanskrit: ''<nowiki/>'ayana'<nowiki/>'' "movement" + ''<nowiki/>'aṃśa''' "component"), to allow for the observed [[precession of equinoxes]], whereas tropical astrology ignores precession.<ref name=":22">{{Cite web|last=Vallée|first=Guylaine|date=2020-03-01|title=What's Your Vedic Astrological Sign?|url=https://www.birla.ca/en/whats-your-vedic-astrological-sign/|access-date=2020-07-29|website=Birla Vedic Center|language=en-US}}</ref> This has caused the two systems, which were aligned around 2,000 years ago, to drift apart over the centuries.<ref name=":22" /><ref name=":0">{{Cite web|last=Subramanian|first=Vijaya|title=Sidereal and Tropical Zodiac – Vijaya Jyoti|url=https://vijayajyoti.com/sidereal-and-tropical-zodiac/|access-date=2020-07-29|language=en}}</ref>

Ayanamsa systems used in Hindu astrology (also known as [[Vedas|Vedic astrology]]) include the Lahiriayanamsa and the Raman ayanamsa.<ref name=":32">{{Cite web|title=Ayanamshas in Sidereal Astrology|url=https://www.astro.com/astrology/in_ayanamsha_e.htm|access-date=2020-07-29|website=www.astro.com|language=en}}</ref> The Fagan-Bradley ayanamsa is an example of an ayanamsa system used in Western sidereal astrology.<ref name=":32" /> As of 2020, zodiacal signs calculated using the Sri Yukteswar ayanamsa were around 23 degrees behind tropical zodiacal signs.<ref name=":22" /> Per these calculations, persons born between March 12 - April 12, for instance, would have the sun sign of Pisces.<ref name=":22" /> By contrast, persons born between March 21 - April 19 would have the sun sign of Aries per tropical calculations.<ref name=":1">{{Cite web|title=Zodiac Sign Dates: What Are The Dates for Every Star Sign?|url=https://astrostyle.com/zodiac-sign-dates/|access-date=2020-07-29|website=Astrostyle: Astrology and Daily, Weekly, Monthly Horoscopes by The AstroTwins|date=28 September 2016 |language=en-US}}</ref>

Sidereal Units:{{sfn|Gupta|2010|p=3}}{{Failed verification|date=April 2022|reason=Many of the measurements in the following table aren't found on page 3 of the book "Units of Measurements", which has a much smaller list. Also not found in the surrounding pages.}}
{| class="wikitable plainrowheaders"
|-
! scope="col" | Unit
! scope="col" | Definition
! scope="col" | Value in [[International System of Units|SI units]]
|-
! scope="row" | ''truti'' ({{lang|sa|त्रुटि}})
| [[Base unit (measurement)|base unit]]
| ≈ 308.6 ns
|-
! scope="row" | ''reṇu'' ({{lang|sa|रेणु}})
| 60 ''truti''
| ≈ 18.5 μs
|-
! scope="row" | ''lava'' ({{lang|sa|लव}})
| 60 ''renu''
| ≈ 1,111 μs
|-
! scope="row" | {{IAST|līkṣaka}} ({{lang|sa|लीक्षक}})
| 60 ''lava''
| ≈ 66.66 [[Millisecond|ms]]
|-
! scope="row" | {{IAST|liptā}}({{lang|sa|लिप्ता}})
| rowspan="2" | 6 {{IAST|līkṣaka}}
| rowspan="2" | ≈ 0.4 s
|-
! scope="row" | ''vipala'' ({{lang|sa|विपल}})
|-
! scope="row" | {{IAST|prāṇa}}<ref>Length of breath in [[Sukhasana]] of healthy person</ref>
({{lang|sa|प्राण}})
| rowspan="1" | 10 {{IAST|liptā}}
| rowspan="1" | ≈ 4 s
|-
! scope="row" | ''pala'' ({{lang|sa|पल}})
| rowspan="3" | 60 {{IAST|liptā}} or 6  {{IAST|prāṇa}}
| rowspan="3" | ≈ 24 s
|-
! scope="row" | {{IAST|vighaṭi}} ({{lang|sa|विघटि}})
|-
! scope="row" | {{IAST|vināḍī}} ({{lang|sa|विनाडी}})
|-
! scope="row" | {{IAST|ghaṭi}} ({{lang|sa|घटि}})
| rowspan="3" | 60 {{IAST|vighaṭi}}
| rowspan="3" | ≈ 1.44 ks (24 min)
|-
! scope="row" | {{IAST|nāḍī}} ({{lang|sa|नाडी}})
|-
! scope="row" | ''daṇḍa'' ({{lang|sa|दण्ड}})
|-
! scope="row" | {{IAST|muhūrta}} ({{lang|sa|मुहूर्त}})
| 2 {{IAST|ghaṭi}}
| ≈ 2.88 ks (48 min)
|-
! scope="row" rowspan="2" | {{IAST|nakṣatra ahorātram}}<br/>([[sidereal day]]; {{lang|sa|नक्षत्र अहोरात्रम्}})
| 60 {{IAST|ghaṭī}}
| rowspan="2" | ≈ 86.4 ks (24 [[hour|h]])
|-
| 30 {{IAST|muhūrta}}
|}

According to {{IAST|Sūrya Siddhānta}}:{{sfn|Burgess|1935|p=6}}<ref>{{Cite web|url=http://veda.wikidot.com/vedic-time-system|title=Vedic Time System - वेद Veda|website=veda.wikidot.com|access-date=2019-12-04}}</ref>
{| class="wikitable plainrowheaders"
|-
! scope="col" | Unit
! scope="col" | Definition
! scope="col" | Value in [[International System of Units|SI units]]
|-
! scope="row" | ''truti''
| [[Base unit (measurement)|base unit]]
| ≈ 29.6 μs
|-
! scope="row" | ''tatpara''
| 100 ''truti''
| ≈ 2.96 ms
|-
! scope="row" | ''nimesha''
| 30 ''tatpara''
| ≈ 88.9 ms
|-
! scope="row" | {{IAST|kāṣṭhā}}
| 18 ''nimesha''
| ≈ 1.6 s
|-
! scope="row" | {{IAST|kalā}}
| 30 {{IAST|kāṣṭhā}}
| ≈ 48 s
|-
! scope="row" | ''ghatika''
| 30 {{IAST|kalā}}
| ≈ 1.44 ks (24 min)
|-
! scope="row" | {{IAST|muhūrta}} ({{IAST|kṣaṇa}})
| 2 ''ghatika''
| ≈ 2.88 ks (48 min)
|-
! scope="row" | {{IAST|ahorātram}}<br/>([[sidereal day]])
| 30 {{IAST|muhūrta}}
| ≈ 86.4 ks (24 [[hour|h]])
|}

Small units of time used in the Vedas:{{sfn|Gupta|2010|p=5}}<ref>{{citation |title=MEASUREMENT UNITS OF LENGTH, MASS AND TIME IN INDIA THROUGH THE AGES |publisher=International Journal of Physical and Social Science |url=https://www.researchgate.net/publication/316599701 |author=Shailaj Kumar Shrivastava |date=May 2017 |access-date=23 December 2020 }}</ref>
{| class="wikitable plainrowheaders"
|-
! scope="col" | Unit
! scope="col" | Definition
! scope="col" | Value in [[International System of Units|SI units]]
|-
! scope="row" | {{IAST|paramāṇu}}
| [[Base unit (measurement)|base unit]]
| ≈ 26.3 μs
|-
! scope="row" | {{IAST|aṇu}}
| 2 {{IAST|paramāṇu}}
| ≈ 52.67 μs
|-
! scope="row" | {{IAST|trasareṇu}}
| 3 {{IAST|aṇu}}
| ≈ 158 μs
|-
! scope="row" | {{IAST|truṭi}}
| 3 {{IAST|trasareṇu}}
| ≈ 474 μs
|-
! scope="row" | ''vedha''
| 100 {{IAST|truṭi}}
| ≈ 47.4 ms
|-
! scope="row" | ''lava''
| 3 ''vedha''
| ≈ 0.14 s
|-
! scope="row" | {{IAST|nimeṣa}}
| 3 ''lava''
| ≈ 0.43 s
|-
! scope="row" | {{IAST|kṣaṇa}}
| 3 {{IAST|nimeṣa}}
| ≈ 1.28 s
|-
! scope="row" | {{IAST|kāṣṭhā}}
| 5 {{IAST|kṣaṇa}}
| ≈ 6.4 s
|-
! scope="row" | ''laghu''
| 15 {{IAST|kāṣṭhā}}
| ≈ 96 s (1.6 min)
|-
! scope="row" | ''danda'' (''nadika'')
| 15 ''laghu''
| ≈ 1.44 ks (24 min)
|-
! scope="row" | {{IAST|muhūrta}}
| 2 ''danda''
| ≈ 2.88 ks (48 min)
|-
! scope="row" | {{IAST|ahorātram}}<br/>([[sidereal day]])
| 30 {{IAST|muhūrta}}
| ≈ 86.4 ks (24 [[hour|h]])
|-
! scope="row" | ''masa'' (month)
| 30 {{IAST|ahorātram}}
| ≈ 2,592 ks
|-
! scope="row" | ''ritu'' (season)
| 2 ''masa''
| ≈ 5,184 ks
|- 
! scope="row" | ''ayana''
| 3 ''ritu''
| ≈ 15,552 ks (6 mth)
|-
! scope="row" | ''samvatsara'' (year)
| rowspan="2" | 2 ''ayana''
| rowspan="2" | ≈ 31,104 ks
|-
! scope="row" | {{IAST|ahorātram}} of Deva
|}

==Lunar metrics==
{{see also | Lunar distance (astronomy) | Orbit of the Moon | Ephemeris | 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.<ref>{{Cite web |title=Introduction to Calendars |url=https://aa.usno.navy.mil/faq/calendars |access-date=2024-08-13 |website=aa.usno.navy.mil}}</ref> 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:{{sfn|Gupta|2010|pp=5–6}}<ref>{{cite book |last=Kumar |first=Ashwini |title=Vaastu: The Art And Science Of Living |url=https://books.google.com/books?id=PwlmRgLt7WkC&pg=PA50 |year=2005 |publisher=Sterling Publishers Pvt. Ltd |isbn=81-207-2569-7 |page=50}}</ref>
{| class="wikitable plainrowheaders"
|-
! scope="col" | Unit
! scope="col" | Definition
! scope="col" | Equivalence
|-
! scope="row" | ''[[tithi]]'' ([[lunar day]])
| Time for 12[[degree (angle)|°]] increase of [[longitude|longitudinal]] angle between Moon and Sun
| ≈ 1 day (varies 19–26 hours)
|-
! scope="row" | [[paksha|{{IAST|pakṣa}}]] ([[lunar fortnight]])
| 15 ''tithis''
| ≈ 15 days
|-
! scope="row" | {{IAST|māsa}} ([[lunar month]])
| 2 {{IAST|pakṣas}}: ''gaura'' (bright) or {{IAST|śukla pakṣa}} during [[Lunar phase#Waxing and waning|waxing moon]]; {{IAST|kṛṣṇa}} (dark) {{IAST|pakṣa}} during [[Lunar phase#Waxing and waning|waning moon]]
| ≈ 30 days (29.5 days)
|-
! scope="row" | [[Ritu (Hindu calendar)|{{IAST|ṛitu}}]] (season)
| 2 {{IAST|māsas}}
| ≈ 60 days
|-
! scope="row" | ''ayanam''
| 3 {{IAST|ṛitus}}
| ≈ 180 days
|-
! scope="row" | ''varsha'' (lunar year)
| 2 ''ayanams''
| ≈ 360 days (354.36707 days)
|}

==Tropical metrics==
{{see also | Tropical year |  Anomalistic 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).<ref>{{Cite journal |last=De |first=Subhadeep |date=2022-06-01 |title=Sundial to the Atomic Clock |url=https://doi.org/10.1007/s12045-022-1390-6 |journal=Resonance |language=en |volume=27 |issue=6 |pages=941–959 |doi=10.1007/s12045-022-1390-6 |issn=0973-712X|url-access=subscription }}</ref> The following section explains these units and their approximate durations, offering insight into how time is organized in relation to the tropical year:{{sfn|Gupta|2010|p=6}}{{efn|Source (Gupta 2010, p. 6) has typo. 4 yāmas is 1/2 day.}}
{| class="wikitable plainrowheaders"
|-
! scope="col" | Unit
! scope="col" | Definition
! scope="col" | Equivalence
|-
! scope="row" |  {{IAST|ghaṭi}} ({{lang|sa|घटि}})
| [[Base unit (measurement)|base unit]]
| ≈ 24 minutes
|-
! scope="row" | {{IAST|yāma}} ({{lang|sa|याम}})
| 7.5 {{IAST|ghaṭis}}
| ≈ 3 hours
|-
! scope="row" | {{IAST|ahorātram}} ({{lang|sa|अहोरात्रम्}})
| 8 {{IAST|yāmas}}
| ≈ 24 hours (tropical day starting at sunrise)
|}

==Cosmic metrics==
The table below contains calculations of cosmic Hindu units of time as experienced by different entities, namely [[human]]s, [[Pitrs|Pitris]] (forefathers), [[Deva (Hinduism)|Devas]] (gods), [[Manu (Hinduism)|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.

<!-- Firefox bug [https://bugzilla.mozilla.org/show_bug.cgi?id=764076] fixed by setting "overflow-y" to "scroll" instead of "auto". -->
{{table alignment}}
{{sticky table start}}
{| class="wikitable sticky-table-row1 sticky-table-col1 plainrowheaders col2left" style="text-align:right;"
|+ Cosmic units of time
! scope="col" | Unit{{efn|name=traditional year|Calculations use a traditional 360-day year (twelve 30-day months) and a standard 24-hour day for all entities:<br>* [[Brahma]]: creator god.<br>* [[Manu (Hinduism)|Manu]]: progenitor of mankind.<br>* [[Deva (Hinduism)|Devas]]: gods, celestials or divine.<br>* [[Pitrs|Pitris]]: forefathers or ancestors.<br>* Humans: year equals Sun's northern and southern movements in Earth's sky ({{aka}} solar or [[tropical year]]).}}
! scope="col" | Definition
! scope="col" | [[Human]]
! scope="col" | [[Pitrs|Pitri]]
! scope="col" | [[Deva (Hinduism)|Deva]]
! scope="col" | [[Manu (Hinduism)|Manu]]
! scope="col" | [[Brahma]]
|-
! scope="row" style="font-weight:bold;" | {{IAST|mahā-kalpa}}
| 36,000 ''kalpa'' & ''pralaya''
| rowspan="2" | 311,040,000,000,000&nbsp;yr
| rowspan="2" | 10,368,000,000,000&nbsp;yr
| rowspan="2" | 864,000,000,000&nbsp;yr
| rowspan="2" | ~{{tooltip|2=7,200,000,000/71 yr ≈ 101,408,450 yr, 8 mo, 13 day, 12 h, 30 min, 25.352 s|101,408,450.70&nbsp;yr}}
| rowspan="2" | 100&nbsp;yr
|-
! scope="row" style="font-weight:bold;" | {{IAST|mahā-pralaya}}
| {{IAST|mahā-kalpa}} length
|-
! scope="row" style="font-weight:bold;" | {{IAST|parārdha}}
| {{frac|1|2}} {{IAST|mahā-kalpa}}
| 155,520,000,000,000&nbsp;yr
| 5,184,000,000,000&nbsp;yr
| 432,000,000,000&nbsp;yr
| ~{{tooltip|2=3,600,000,000/71 yr ≈ 50,704,225 yr, 4 mo, 6 day, 18 h, 15 min, 12.676 s|50,704,225.35&nbsp;yr}}
| 50&nbsp;yr
|-
! scope="row" style="font-weight:bold;" | ''[[Kalpa (time)|kalpa]]''
| 14&nbsp;m + 15&nbsp;ms; 1,000&nbsp;cy
| rowspan="2" | 4,320,000,000&nbsp;yr
| rowspan="2" | 144,000,000&nbsp;yr
| rowspan="2" | 12,000,000&nbsp;yr
| rowspan="2" | ~{{tooltip|2=100,000/71 yr ≈ 1,408 yr, 5 mo, 12 day, 6 h, 5 min, 4.225 s|1,408.45&nbsp;yr}}
| rowspan="2" | 12&nbsp;h
|-
! scope="row" style="font-weight:bold;" | ''[[pralaya]]''
| ''kalpa'' length
|-
! scope="row" style="font-weight:bold;" | ''[[manvantara]]'' [m]
| 71 {{IAST|catur-yuga}}
| 306,720,000&nbsp;yr
| 10,224,000&nbsp;yr
| 852,000&nbsp;yr
| 100&nbsp;yr
| {{tooltip|2=71/720,000 yr {{=}} 51 min, 7.200 s|51.12&nbsp;min}}
|-
! scope="row" style="font-weight:bold;" | {{IAST|manvantara-sandhyā}} [ms]
| {{IAST|Kṛta-yuga}} length
| 1,728,000&nbsp;yr
| 57,600&nbsp;yr
| 4,800&nbsp;yr
| ~{{tooltip|2=40/71 yr ≈ 6 mo, 22 day, 19 h, 36 min, 20.282 s|6.76&nbsp;mo}}
| 17.28&nbsp;s
|-
! scope="row" style="font-weight:bold;" | [[Yuga Cycle|{{IAST|catur-yuga}}]] [cy]
| {{IAST|Kṛta}}, {{IAST|Tretā}}, {{IAST|Dvāpara}} & ''Kali-yugas''
| 4,320,000&nbsp;yr
| 144,000&nbsp;yr
| 12,000&nbsp;yr
| ~{{tooltip|2=100/71 yr ≈ 1 yr, 4 mo, 27 day, 1 h, 0 min, 50.704 s|1.41&nbsp;yr}}
| 43.20&nbsp;s
|-
| colspan="7" | &nbsp;
|-
! scope="row" style="font-weight:bold;" | [[Satya Yuga|{{IAST|Kṛta-yuga}}]]
| sum total
| 1,728,000&nbsp;yr
| 57,600&nbsp;yr
| 4,800&nbsp;yr
| ~{{tooltip|2=40/71 yr ≈ 6 mo, 22 day, 19 h, 36 min, 20.282 s|6.76&nbsp;mo}}
| 17.28&nbsp;s
|-
! scope="row" | {{IAST|Kṛta-yuga-sandhyā}}
| rowspan="2" | {{frac|1|10}} {{IAST|Kṛta-yuga}}{{efn|name="yuga proper"}} length
| rowspan="2" | 144,000&nbsp;yr
| rowspan="2" | 4,800&nbsp;yr
| rowspan="2" | 400&nbsp;yr
| rowspan="2" | ~{{tooltip|2=10/213 yr ≈ 16 day, 21 h, 38 min, 1.690 s|16.90&nbsp;day}}
| rowspan="2" | 1.44&nbsp;s
|-
! scope="row" | {{IAST|Kṛta-yuga-sandhyāṃśa}}
|-
! scope="row" | {{IAST|Kṛta-yuga}}{{efn|name="yuga proper"}}
| 4 ''Kali-yuga''{{efn|name="yuga proper"}} lengths
| 1,440,000&nbsp;yr
| 48,000&nbsp;yr
| 4,000&nbsp;yr
| ~{{tooltip|2=100/213 yr ≈ 5 mo, 19 day, 0 h, 20 min, 16.901 s|5.63&nbsp;mo}}
| 14.40&nbsp;s
|-
| colspan="7" | &nbsp;
|-
! scope="row" style="font-weight:bold;" | [[Treta Yuga|{{IAST|Tretā-yuga}}]]
| sum total
| 1,296,000&nbsp;yr
| 43,200&nbsp;yr
| 3,600&nbsp;yr
| ~{{tooltip|2=30/71 yr ≈ 5 mo, 2 day, 2 h, 42 min, 15.211 s|5.07&nbsp;mo}}
| 12.96&nbsp;s
|-
! scope="row" | {{IAST|Tretā-yuga-sandhyā}}
| rowspan="2" | {{frac|1|10}} {{IAST|Tretā-yuga}}{{efn|name="yuga proper"}} length
| rowspan="2" | 108,000&nbsp;yr
| rowspan="2" | 3,600&nbsp;yr
| rowspan="2" | 300&nbsp;yr
| rowspan="2" | ~{{tooltip|2=10/284 yr ≈ 12 day, 16 h, 13 min, 31.268 s|12.68&nbsp;day}}
| rowspan="2" | 1.08&nbsp;s
|-
! scope="row" | {{IAST|Tretā-yuga-sandhyāṃśa}}
|-
! scope="row" | {{IAST|Tretā-yuga}}{{efn|name="yuga proper"}}
| 3 ''Kali-yuga''{{efn|name="yuga proper"}} lengths
| 1,080,000&nbsp;yr
| 36,000&nbsp;yr
| 3,000&nbsp;yr
| ~{{tooltip|2=100/284 yr ≈ 4 mo, 6 day, 18 h, 15 min, 12.676 s|4.23&nbsp;mo}}
| 10.80&nbsp;s
|-
| colspan="7" | &nbsp;
|-
! scope="row" style="font-weight:bold;" | [[Dvapara Yuga|{{IAST|Dvāpara-yuga}}]]
| sum total
| 864,000&nbsp;yr
| 28,800&nbsp;yr
| 2,400&nbsp;yr
| ~{{tooltip|2=20/71 yr ≈ 3 mo, 11 day, 9 h, 48 min, 10.141 s|3.38&nbsp;mo}}
| 8.64&nbsp;s
|-
! scope="row" | {{IAST|Dvāpara-yuga-sandhyā}}
| rowspan="2" | {{frac|1|10}} {{IAST|Dvāpara-yuga}}{{efn|name="yuga proper"}} length
| rowspan="2" | 72,000&nbsp;yr
| rowspan="2" | 2,400&nbsp;yr
| rowspan="2" | 200&nbsp;yr
| rowspan="2" | ~{{tooltip|2=10/426 yr ≈ 8 day, 10 h, 49 min, 0.845 s|8.45&nbsp;day}}
| rowspan="2" | 0.72&nbsp;s
|-
! scope="row" | {{IAST|Dvāpara-yuga-sandhyāṃśa}}
|-
! scope="row" | {{IAST|Dvāpara-yuga}}{{efn|name="yuga proper"}}
| 2 ''Kali-yuga''{{efn|name="yuga proper"}} lengths
| 720,000&nbsp;yr
| 24,000&nbsp;yr
| 2,000&nbsp;yr
| ~{{tooltip|2=100/426 yr ≈ 2 mo, 24 day, 12 h, 10 min, 8.451 s|2.82&nbsp;mo}}
| 7.20&nbsp;s
|-
| colspan="7" | &nbsp;
|-
! scope="row" style="font-weight:bold;" | ''[[Kali Yuga|Kali-yuga]]''
| sum total
| 432,000&nbsp;yr
| 14,400&nbsp;yr
| 1,200&nbsp;yr
| ~{{tooltip|2=10/71 yr ≈ 1 mo, 20 day, 16 h, 54 min, 5.070 s|1.69&nbsp;mo}}
| 4.32&nbsp;s
|-
! scope="row" | {{IAST|Kali-yuga-sandhyā}}
| rowspan="2" | {{frac|1|10}} ''Kali-yuga''{{efn|name="yuga proper"}} length
| rowspan="2" | 36,000&nbsp;yr
| rowspan="2" | 1,200&nbsp;yr
| rowspan="2" | 100&nbsp;yr
| rowspan="2" | ~{{tooltip|2=10/852 yr ≈ 4 day, 5 h, 24 min, 30.423 s|4.23&nbsp;day}}
| rowspan="2" | 0.36&nbsp;s
|-
! scope="row" | {{IAST|Kali-yuga-sandhyāṃśa}}
|-
! scope="row" | ''Kali-yuga''{{efn|name="yuga proper"|Main part of ''yuga'' (''yuga'' proper); occurs after its {{IAST|sandhyā}} (dawn) and before its {{IAST|sandhyāṃśa}} (dusk).}}
| 1,000 Deva years
| 360,000&nbsp;yr
| 12,000&nbsp;yr
| 1,000&nbsp;yr
| ~{{tooltip|2=100/852 yr ≈ 1 mo, 12 day, 6 h, 5 min, 4.225 s|1.41&nbsp;mo}}
| 3.60&nbsp;s
|}
{{sticky table end}}

===Lifespans===
[[Hindu texts]] define lifespans differently for [[human]]s, [[Pitrs|Pitris]] (forefathers), [[Deva (Hinduism)|Devas]] (gods), [[Manu (Hinduism)|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.<ref>{{cite book |author-first=Buddhike Sri Harsha |author-last=Indrasena |year=2021 |orig-year=2020 |title=Resolving the Controversies of Astrology and Vedic Astronomy: Thinking Outside the Box |url=https://books.google.com/books?id=fTbyDwAAQBAJ |edition=Revised |publisher=[[Lulu.com|Lulu Press]] |pages=81–82 |isbn=978-1-716-75246-9 |quote=6.2.2: For all human, divine, and Brahma scales, one year equals 360 'days' of respective scale.}}</ref> 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,{{efn|A human year is divided into twelve equal months, measured by the sun's six month movements in the north [https://vedabase.io/en/library/bg/8/24/ BG 8.24] and south [https://vedabase.io/en/library/bg/8/25/ BG 8.25], as indicated in ''Bhagavad-gita''.}} 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).{{sfn|Burgess|1935|p=41}} For this reason, a traditional 360-day year is equivalent to a modern ~365.24-day solar or [[tropical year]].

<div style="overflow: auto;">
{| class="wikitable plainrowheaders" style="text-align:right;"
|+
! scope="col" | Unit{{efn|name=traditional year}}
! scope="col" | [[Human]]
! scope="col" | [[Pitrs|Pitri]]
! scope="col" | [[Deva (Hinduism)|Deva]]
! scope="col" | [[Manu (Hinduism)|Manu]]
! scope="col" | [[Brahma]]
|-
! scope="row" | Brahma year
| 3,110,400,000,000&nbsp;yr
| 103,680,000,000&nbsp;yr
| 8,640,000,000&nbsp;yr
| ~{{tooltip|2=72,000,000/71 yr ≈ 1,014,084 yr, 6 mo, 2 day, 12 h, 50 min, 42.254 s|1,014,084.51&nbsp;yr}}
| style="font-weight:bold;" | 1&nbsp;yr
|-
! scope="row" | Manu year
| 3,067,200&nbsp;yr
| 102,240&nbsp;yr
| 8,520&nbsp;yr
| style="font-weight:bold;" | 1&nbsp;yr
| {{tooltip|2=71/72,000,000 yr {{=}} 30.672 s|30.67&nbsp;s}}
|-
! scope="row" | Deva year
| 360&nbsp;yr
| 12&nbsp;yr
| style="font-weight:bold;" | 1&nbsp;yr
| ~{{tooltip|2=1/8,520 yr ≈ 1 h, 0 min, 50.704 s|1.01&nbsp;h}}
| {{tooltip|2=1/8,640,000,000 yr|3.60&nbsp;[[Millisecond|ms]]}}
|-
! scope="row" | Pitri year
| 30&nbsp;yr
| style="font-weight:bold;" | 1&nbsp;yr
| {{tooltip|2=1/12 yr|1&nbsp;mo}}
| ~{{tooltip|2=1/102,240 yr ≈ 5 min, 4.225 s|5.07&nbsp;min}}
| {{tooltip|2=1/103,680,000,000 yr|300&nbsp;[[Microsecond|μs]]}}
|-
! scope="row" | Human year
| style="font-weight:bold;" | 1&nbsp;yr
| {{tooltip|2=1/30 yr|12&nbsp;day}}
| {{tooltip|2=1/360 yr|1&nbsp;day}}
| ~{{tooltip|2=1/3,067,200 yr ≈ 10.141 s|10.14&nbsp;s}}
| {{tooltip|2=1/3,110,400,000,000 yr|10&nbsp;[[Microsecond|μs]]}}
|}
</div>

===Cosmic date===
{{See also|Kali Yuga#Start date}}

According to [[Purana|Puranic sources]],{{efn|The ''[[Bhagavata Purana]]'' (1.18.6),<ref>{{Cite book |chapter=Skanda I, Ch. 18: Curse of the Brahmana, Sloka 6 |title=Bhagavata Purana |chapter-url=https://archive.org/details/BhagavataPuranaMotilalEnglish/page/n141/mode/1up |volume=Part I |publisher=[[Motilal Banarsidass|Motilal Banarsidass Publishers Private Limited]] |year=1950 |page=137 |quote=On the very day, and at the very moment the Lord [Krishna] left the earth, on that very day this Kali, the source of irreligiousness, (in this world), entered here.}}</ref> ''[[Vishnu Purana]]'' (5.38.8),<ref>{{Cite book |author-last=Wilson |author-first=H. H. |author-link=Horace Hayman Wilson |year=1895 |chapter=Book V, Ch. 38: Arjuna burns the dead, etc., Sloka 8 |title=The Vishnu Purana |chapter-url=https://archive.org/details/in.ernet.dli.2015.47536/page/n73/mode/1up |publisher=S.P.C.K. Press |page=61 |quote=The Parijata tree proceeded to heaven, and on the same day that Hari [Krishna] departed from the earth the dark-bodied Kali age descended.}}</ref> ''[[Brahmanda Purana]]'' (2.3.74.241),<ref>{{Cite book |chapter=Ch. 74, Royal Dynasties, Sloka 241 |title=The Brahmanda Purana |chapter-url=https://archive.org/details/dli.bengal.10689.12922/page/n238/mode/1up |volume=Part III |publisher=[[Motilal Banarsidass]] |year=1958 |page=950 |quote=Kali Yuga began on the day when Krsna passed on to heaven. Understand how it is calculated.}}</ref> ''[[Vayu Purana]]'' (2.37.422),<ref>{{Cite book |chapter=Ch. 37, Royal Dynasties, Sloka 422 |title=The Vayu Purana |chapter-url=https://archive.org/details/the-vayu-purana-part-2-ancient-indian-tradition-and-mythology/page/824/mode/1up |volume=Part II |publisher=[[Motilal Banarsidass]] |year=1988 |page=824 | isbn=81-208-0455-4 |quote=Kali Yuga had started on the very day when Krsna passed away.}}</ref> and ''[[Brahma Purana]]'' (2.103.8)<ref>{{Cite book |chapter=Ch. 103, Episode of Krsna concluded, Sloka 8 |title=Brahma Purana |chapter-url=https://archive.org/details/in.ernet.dli.2015.98294/page/n285/mode/1up |volume=Part II |publisher=[[Motilal Banarsidass]] |year=1955 |page=515 |quote=It was on the day on which Krishna left the Earth and went to heaven that the Kali age, with time for its body set in.}}</ref> state that the day [[Krishna]] left the earth was the day that the ''[[Dvapara Yuga]]'' ended and the ''[[Kali Yuga]]'' began}} [[Krishna|Krishna's]] departure marks the end of the human age of ''[[Dvapara Yuga|Dvapara-yuga]]'' and the start of ''[[Kali Yuga|Kali-yuga]]'', which is dated to midnight on 17/18 February 3102{{nbsp}}[[Common Era|BCE]] of the [[proleptic Julian calendar]]. We are currently halfway through [[Brahma|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 (time)|kalpa]]'' cycles:<ref name="Krishnamurthy 2019" />{{sfn|Gupta|2010|pp=7–8}}{{sfn|Godwin|2011|p=301|ps=: ''[[Vishnu Purana]]'', translated by the great Sanskritist [[Horace Hayman Wilson]]: One Pararddha, or half [Brahma's] existence, has expired, terminating with the Maha Kalpa called Padma. The Kalpa (or day of Brahma) termed Varaha is the first of the second period of Brahma's existence. ... The Hindu astronomers agree that the Kali Yuga began at midnight between February 17 and 18, 3102 BCE. Consequently it is due to end about 427,000 CE, whereupon a new Golden Age will dawn.}}<ref>{{cite book |author-last=Burgess |author-first=Ebenezer |year=1860 |chapter=Ch. I, Of the Mean Motions of the Planets |title=Translation of the Sûrya-Siddhânta: A text-book of Hindu astronomy, with notes and an appendix |chapter-url=https://books.google.com/books?id=jpE7AAAAcAAJ&pg=PA10 |publisher=[[Journal of the American Oriental Society]] |pages=10–12 (1.21–24), 17}}</ref><ref name="Blackwell Companion to Hinduism">{{cite book |author-last1=Matchett |author-first1=Freda |author-last2=Yano |author-first2=Michio |year=2003 |chapter=Part II, Ch. 6: The Puranas / Part III, Ch. 18: Calendar, Astrology, and Astronomy |editor-last=Flood |editor-first=Gavin |editor-link=Gavin Flood |title=The Blackwell Companion to Hinduism |chapter-url=https://books.google.com/books?id=SKBxa-MNqA8C&q=yuga&pg=PA139 |publisher=[[Blackwell Publishing]] |pages=139–140, 390 (Kali yuga epoch) |isbn=0631215352}}</ref>
* 51st year of 100 (2nd half or ''parardha'')
* 1st month of 12
* 1st ''[[Kalpa (time)|kalpa]]'' (''Shveta-Varaha Kalpa'') of 30
* 7th ''[[manvantara]]'' ([[Shraddhadeva Manu|Vaivasvatha Manu]]) of 14
* 28th ''[[Yuga Cycle|chatur-yuga]]'' of 71
* 4th ''[[yuga]]'' (''[[Kali Yuga|Kali-yuga]]'') of 4

A ''maha-kalpa'' is followed by a ''[[Pralaya|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'' ({{aka}} ''[[Satya Yuga|Satya-yuga]]'').<ref name="Krishnamurthy 2019" />{{sfn|Gupta|2010|pp=7–8}}

[[Hindu texts]] specify that the start and end of each of the ''yugas'' are marked by astronomical alignments. This cycle's ''[[Treta Yuga|Treta-yuga]]'' began with 5 planets residing in the "Aries" constellation. This cycle's ''[[Dvapara Yuga|Dvapara-yuga]]'' ended with the "Saptarshi" constellation (Ursa major) residing in the "Magha" constellation. The current ''[[Kali Yuga|Kali-yuga]]'' will end with the Sun, Moon and Jupiter residing in the "Pushya" sector.<ref>[https://legendofbharatbarsha.home.blog/2019/12/07/detailed-history-of-time/ Bharatbarsha – A Living Legend].</ref>{{Better source needed|reason=Cited website doesn't properly cite any works.|date=October 2020}}

===Human===
{{Main|Yuga Cycle}}

The history of humanity is divided up into [[Yuga Cycle|four ''yugas'']] ({{aka}} ''[[Dharma#Hinduism|dharmic]]'' ages or world ages)—{{IAST|Kṛta-yuga}} (pronounced ''Krita-yuga''; {{aka}} ''[[Satya Yuga|Satya-yuga]]''), [[Treta Yuga|{{IAST|Tretā-yuga}}]], [[Dvapara Yuga|{{IAST|Dvāpara-yuga}}]] and ''[[Kali Yuga|Kali-yuga]]''—each with a 25% decline in ''dharmic'' practices and length, giving proportions ({{IAST|caraṇas}}; pronounced ''charanas'') of 4:3:2:1 (e.g. ''Satya'': 100% start; ''Kali'': 25% start, 0% end), indicating a [[Devolution (biology)|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 [[Yuga Cycle|{{IAST|catur-yuga}}]] (pronounced ''chatur-yuga''; {{aka}} ''mahā-yuga''). Each ''yuga'' is divided into a main period ({{aka}} ''yuga'' proper) and two ''yuga-sandhis'' ({{aka}} {{IAST|yuga-sandhyās}}; connecting periods)⁠—{{IAST|yuga-sandhyā}} (dawn) and {{IAST|yuga-sandhyāṃśa}} ({{aka}} {{IAST|yuga-sandhyānśa}}; dusk)⁠—where each ''yuga-sandhi'' lasts for 10% of the main period. Lengths are given in divine years ({{aka}} celestial or [[Deva (Hinduism)|Deva]] years), where a divine year lasts for 360 [[Tropical year|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''.{{sfn|Gupta|2010|p=7}}<ref>{{cite book |author-last=Godwin |author-first=Joscelyn |author-link=Joscelyn Godwin |year=2011 |title=Atlantis and the Cycles of Time: Prophecies, Traditions, and Occult Revelations |url=https://archive.org/details/joscelyngodwinatlantisandthecyclesoftimepropheciestraditionsandoccultrevelations/page/n312/mode/1up |publisher=[[Inner Traditions]] |isbn=9781594778575 |pages=300–301}}</ref><ref>{{cite encyclopedia |author=Merriam-Webster |year=1999 |editor-last1=Doniger |editor-first1=Wendy |editor-link1=Wendy Doniger |editor-last2=Hawley |editor-first2=John Stratton |title=Merriam-Webster's Encyclopedia of World Religions |url=https://archive.org/details/isbn_9780877790440 |url-access=registration |encyclopedia=[[Merriam-Webster]] |publisher=[[Merriam-Webster|Merriam-Webster, Incorporated]] |pages=[https://archive.org/details/isbn_9780877790440/page/445/mode/1up 445 (Hinduism)], [https://archive.org/details/isbn_9780877790440/page/1159/mode/1up 1159 (Yuga)] |isbn=0877790442 |quote=<br>* 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.<br>* 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 ... 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.}}</ref><ref name="Hans Kng 50">{{cite book|url=https://books.google.com/books?id=sm0BfUKwct0C&q=4,000+%2B+400+%2B+400+%3D+4,800+divine+years+(%3D+1,728,000+human+years)&pg=PA50|title=Tracing The Way: Spiritual Dimensions of the World Religions|publisher=[[A&C Black]]|page=50|author=Hans Kng|isbn=9780826494238|date=31 October 2006}}</ref><ref>{{cite web |title=Śrīmad-Bhāgavatam (Bhāgavata Purāṇa) 3.11.19 |url=https://vedabase.io/en/library/sb/3/11/19/ |website=Bhaktivedanta Vedabase |access-date=2020-07-10 |quote=<br>{{transliteration|sa|catvāri trīṇi dve caikaṁ kṛtādiṣu yathā-kramam ।<br>saṅkhyātāni sahasrāṇi dvi-guṇāni śatāni ca ॥ 19 ॥|italic=no}}<br>(19) The duration of the Satya millennium equals 4,800 years of the years of the demigods; the duration of the Tretā millennium equals 3,600 years of the demigods; the duration of the Dvāpara millennium equals 2,400 years; and that of the Kali millennium is 1,200 years of the demigods. PURPORT: As aforementioned, one year of the demigods is equal to 360 years of the human beings. The duration of the Satya-yuga is therefore 4,800 × 360, or 1,728,000 years. The duration of the Tretā-yuga is 3,600 × 360, or 1,296,000 years. The duration of the Dvāpara-yuga is 2,400 × 360, or 864,000 years. And the last, the Kali-yuga, is 1,200 × 360, or 432,000 years.}}</ref>{{efn|''[[Vishnu Purana]]'', Book I, Ch. III}}

====Current ''yuga''====
''[[Kali Yuga|Kali-yuga]]'' lasts for 432,000 years and is the 4th of 4 ''[[Yuga Cycle|yugas in a cycle]]'' as well as the current ''yuga'', with two ''sandhyas'', each lasting for 36,000 years:{{efn|name=Current time math|Calculations as of midnight on 17/18 February {{CURRENTYEAR}}{{nbsp}}[[Common Era|CE]]. Note, the number of years from 1{{nbsp}}[[Common Era|BCE]] to 1{{nbsp}}[[Common Era|CE]] is 1 year and not 2 years since there is no [[year zero]].}}
* ''Kali-yuga'' started 3102{{nbsp}}BCE in past:
: = current year + ''Kali-yuga'' start year - [[year zero]]
: = {{CURRENTYEAR}} + 3102 - 1
: = {{val|{{sum
  |{{CURRENTYEAR}}
  |3102
  |-1
  }}|fmt=commas}} years
* ''Kali-yuga-sandhya'' (dawn) ends {{formatnum:{{sum|36000|-3102|1}}}}{{nbsp}}CE in future:
: = ''Kali-yuga-sandhya'' - elapsed ''Kali-yuga''
: = 36,000 - ({{CURRENTYEAR}} + 3102 - 1)
: = {{val|{{sum
  |36000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  }}|fmt=commas}} years
* ''Kali-yuga-sandhyamsa'' (dusk) starts {{formatnum:{{sum|432000|-36000|-3102|1}}}}{{nbsp}}CE in future:
: = ''Kali-yuga'' - ''Kali-yuga-sandhyamsa'' - elapsed ''Kali-yuga''
: = 432,000 - 36,000 - ({{CURRENTYEAR}} + 3102 - 1)
: = {{val|{{sum
  |432000
  |-36000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  }}|fmt=commas}} years
* ''Kali-yuga'' ends {{formatnum:{{sum|432000|-3102|1}}}}{{nbsp}}CE in future:
: = ''Kali-yuga'' - elapsed ''Kali-yuga''
: = 432,000 - ({{CURRENTYEAR}} + 3102 - 1)
: = {{val|{{sum
  |432000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  }}|fmt=commas}} years

====Current ''chatur yuga''====
A ''[[Yuga Cycle|chatur-yuga]]'' lasts for 4.32{{nbsp}}million years, where the current is the 28th of 71:{{efn|name=Current time math}}
* Started {{formatnum:{{sum|4320000|-432000|3102}}}}{{nbsp}}BCE in past:
: = ''chatur-yuga'' - ''Kali-yuga'' + elapsed ''Kali-yuga''
: = 4,320,000 - 432,000 + ({{CURRENTYEAR}} + 3102 - 1)
: = {{val|{{sum
  |4320000
  |-432000
  |{{CURRENTYEAR}}
  |3102
  |-1
  }}|fmt=commas}} years
: ≈ {{round|{{multiply|{{sum
  |4320000
  |-432000
  |{{CURRENTYEAR}}
  |3102
  |-1
  }}|1/1,000,000|r=1|nosep=1}}|2}} million years
* Ends {{formatnum:{{sum|432000|-3102|1}}}}{{nbsp}}CE in future:
: = ''Kali-yuga'' - elapsed ''Kali-yuga''
: = 432,000 - ({{CURRENTYEAR}} + 3102 - 1)
: = {{val|{{sum
  |432000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  }}|fmt=commas}} years

{| class="wikitable plainrowheaders" style="border-width:0; text-align:right;"
|+ 28th ''[[Yuga Cycle|chatur-yuga]]''
|-
! scope="col" | ''Yuga''
! scope="col" | Start (– End)
! scope="col" | Length
|-
! scope="row" | ''[[Satya Yuga|Krita (Satya)]]''
| 3,891,102{{nbsp}}BCE
| class="nowrap" | 1,728,000 (4,800)
|-
! scope="row" | ''[[Treta Yuga|Treta]]''
| 2,163,102{{nbsp}}BCE
| class="nowrap" | 1,296,000 (3,600)
|-
! scope="row" | ''[[Dvapara Yuga|Dvapara]]''
| 867,102{{nbsp}}BCE
| class="nowrap" | 864,000 (2,400)
|-
! scope="row" | ''[[Kali Yuga|Kali]]*''
| 3102{{nbsp}}BCE{{snd}}428,899{{nbsp}}CE
| class="nowrap" | 432,000 (1,200)
|-
| colspan="3" style="background-color:#ffffff; font-weight:bold; padding-top:5px;" | Years: 4,320,000 [[Tropical year|solar]] (12,000 divine)
|-
| colspan="2" style="background-color:#ffffff; border-width:1px 0 0 0; font-size:80%; padding-top:0; text-align:left;" | {{sup|(*) Current.}}
| style="background-color:#ffffff; border-width:1px 0 0 0; padding-top:0;" | {{efn|Each ''Kali-yuga-sandhi'' lasts for 36,000 solar (100 divine) years:<br>* ''Sandhya'': 3102{{nbsp}}BCE{{snd}}32,899{{nbsp}}CE<br>* ''Sandhyamsa'': 392,899–428,899{{nbsp}}CE}}{{sfn|Godwin|2011|p=301|ps=: ''[[Vishnu Purana]]'', translated by the great Sanskritist [[Horace Hayman Wilson]]: One Pararddha, or half [Brahma's] existence, has expired, terminating with the Maha Kalpa called Padma. The Kalpa (or day of Brahma) termed Varaha is the first of the second period of Brahma's existence. ... The Hindu astronomers agree that the Kali Yuga began at midnight between February 17 and 18, 3102 BCE. Consequently it is due to end about 427,000 CE, whereupon a new Golden Age will dawn.}}{{sfn|Burgess|1935|p=ix (Introduction)|ps=: Calculated date of 2163102 B.C. for "the end of the Golden Age (Krta yuga)", the start of Treta yuga, mentioned in [[Surya Siddhanta]] 1.57.}}
|}

===Pitri===
The lifespan of the [[Pitrs|Pitris]] (forefathers) lasts for 100 of their years.{{sfn|Gupta|2010|p=6}}
* 24 hours (1 day & night) of Pitris = 1 solar month (''masa''; Moon's two 15-day fortnights: bright and dark)
* 30 days (1 month) of Pitris = 30 solar months (2.5 solar years)
* 12 months (1 year) of Pitris = 30 solar years (1 month of [[Deva (Hinduism)|Devas]])
* 100 years (lifespan) of Pitris = 3,000 solar years

===Deva===
The lifespan of the [[Deva (Hinduism)|Devas]] (gods) lasts for 100 of their years.{{sfn|Gupta|2010|p=6}}
* 24 hours (1 day & night) of Devas = 1 solar year (Sun's two 180-day motions: northern and southern)
* 30 days (1 month) of Devas = 30 solar years (1 year of [[Pitrs|Pitris]])
* 12 months (1 year) of Devas = 360 solar years
* 100 years (lifespan) of Devas = 36,000 solar years

===Manu===
{{Main|Manvantara}}

The lifespan of the [[Manu (Hinduism)|Manus]] (progenitors of mankind) lasts for 100 of their years. Each Manu reigns over a period called a ''[[manvantara]]'', each lasting for 71 ''[[Yuga Cycle|chatur-yugas]]'' (306.72 million years). A total of 14 Manus reign successively in one ''[[Kalpa (time)|kalpa]]'' (day of [[Brahma]]). Preceding the first and following each ''manvantara'' is a ''{{IAST|sandhyā}}'' (connection period), each lasting the duration of ''[[Satya Yuga|Satya-yuga]]'' (1.728 million years). During each ''{{IAST|manvantara-sandhyā}}'' ({{aka}} ''manvantara-sandhi''), Earth (''[[Loka#Hinduism|Bhu-loka]]'') is submerged in water.<ref name="Krishnamurthy 2019">{{cite book |author-last=Krishnamurthy |author-first=V. |year=2019 |chapter=Ch. 20: The Cosmic Flow of Time as per Scriptures |title=Meet the Ancient Scriptures of Hinduism |chapter-url=https://books.google.com/books?id=HF2NDwAAQBAJ&q=%227th+manvantara%22+%2228th%22&pg=PT407 |publisher=Notion Press |isbn=9781684669387 |quote=Each manvantara is preceded and followed by a period of 1,728,000 (= 4K) years when the entire earthly universe (bhu-loka) will submerge under water. The period of this deluge is known as manvantara-sandhya (sandhya meaning, twilight). ... According to the traditional time-keeping ... Thus in Brahma's calendar the present time may be coded as his 51st year - first month - first day - 7th manvantara - 28th maha-yuga - 4th yuga or kaliyuga.}}</ref>{{sfn|Gupta|2010|p=7}}<ref>{{cite encyclopedia |editor-last1=Doniger |editor-first1=Wendy |editor-link1=Wendy Doniger |editor-last2=Hawley |editor-first2=John Stratton |year=1999 |title=Merriam-Webster's Encyclopedia of World Religions |url=https://archive.org/details/isbn_9780877790440 |url-access=registration |encyclopedia=[[Merriam-Webster]] |publisher=[[Merriam-Webster|Merriam-Webster, Incorporated]] |page=691 (Manu) |isbn=0877790442 |quote=a day in the life of Brahma is divided into 14 periods called manvantaras ("Manu intervals"), each of which lasts for 306,720,000 years. In every second cycle [(new kalpa after pralaya)] the world is recreated, and a new Manu appears to become the father of the next human race. The present age is considered to be the seventh Manu cycle.}}</ref><ref name="Bryan E. Penprase 182">{{cite book |author-last=Penprase |author-first=Bryan E. |year=2017 |url=https://books.google.com/books?id=pQHNDgAAQBAJ |title=The Power of Stars |edition=2nd |publisher=[[Springer Science+Business Media|Springer]] |page=182 |isbn=9783319525976}}</ref>
* 24 hours (1 day & night) of Manu = 8,520 solar years
* 30 days (1 month) of Manu = 255,600 solar years
* 12 months (1 year) of Manu = 3,067,200 solar years
* 100 years (lifespan) of Manu = 306,720,000 solar years (71 ''[[Yuga Cycle|chatur-yugas]]'')

====Current ''manvantara''====
A ''[[manvantara]]'' lasts for 306.72{{nbsp}}million years, where the current (ruled by [[Shraddhadeva Manu|Vaivasvatha Manu]]) is the 7th of 14:{{efn|name=Current time math}}
* Started in past:
: = elapsed 28th ''chatur-yuga'' + 27 ''chatur-yugas''
: = ''chatur-yuga'' - ''Kali-yuga'' + elapsed ''Kali-yuga'' + 27 ''chatur-yugas''
: = (4,320,000 - 432,000 + ({{CURRENTYEAR}} + 3102 - 1)) + 4,320,000 * 27
: = {{val|{{sum
  |4320000
  |-432000
  |{{CURRENTYEAR}}
  |3102
  |-1
  |{{multiply|4,320,000|27|r=1|nosep=1}}
  }}|fmt=commas}} years
: ≈ {{round|{{multiply|{{sum
  |4320000
  |-432000
  |{{CURRENTYEAR}}
  |3102
  |-1
  |{{multiply|4,320,000|27|r=1|nosep=1}}
  }}|1/1,000,000|r=1|nosep=1}}|2}} million years
* Ends in future:
: = remaining 28th ''chatur-yuga'' + 43 ''chatur-yugas''
: = ''Kali-yuga'' - elapsed ''Kali-yuga'' + 43 ''chatur-yugas''
: = (432,000 - ({{CURRENTYEAR}} + 3102 - 1)) + 4,320,000 * 43
: = {{val|{{sum
  |432000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  |{{multiply|4,320,000|43|r=1|nosep=1}}
  }}|fmt=commas}} years
: ≈ {{round|{{multiply|{{sum
  |432000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  |{{multiply|4,320,000|43|r=1|nosep=1}}
  }}|1/1,000,000|r=1|nosep=1}}|2}} million years

===Brahma===
{{Main|Kalpa (time)}}

The lifespan of [[Brahma]] (creator god) lasts for 100 of his years. His 12-hour day or ''[[Kalpa (time)|kalpa]]'' ({{aka}} day of Brahma) is followed by a 12-hour night or ''[[pralaya]]'' ({{aka}} night of Brahma) of equal length, each lasting for 4.32 billion years. A ''kalpa'' lasts for 1,000 ''[[Yuga Cycle|chatur-yugas]]'' and has 14 ''[[manvantara]]s'' 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 {{IAST|mahā-kalpa}}, which is followed by a {{IAST|mahā-pralaya}} (full dissolution) of equal length, where the bases of the universe, ''[[Prakṛti|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 {{IAST|parārdha}}.{{sfn|Gupta|2010|pp=7–8}}<ref name="Bryan E. Penprase 182"/><ref name=Johnson2009>{{cite book|last=Johnson|first=W.J.|title=A Dictionary of Hinduism|publisher=Oxford University Press|year=2009|isbn=978-0-19-861025-0|page=165}}</ref> 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).

* 12 hours (1 day proper: ''kalpa'') of Brahma = 4.32&nbsp;billion solar years (1,000 ''[[Yuga Cycle|chatur-yugas]]''; 14 ''[[manvantara]]s'' + 15 ''manvantara-sandhyas'')
* 24 hours (1 day & night: ''kalpa'' + ''pralaya'') of Brahma = 8.64&nbsp;billion solar years
* 30 days (1 month) of Brahma = 259.2&nbsp;billion solar years
* 12 months (1 year) of Brahma = 3.1104&nbsp;trillion solar years
* 50 years (''parardha'') of Brahma = 155.52&nbsp;trillion solar years
* 100 years (lifespan: 2 ''parardhas'') of Brahma = 311.04&nbsp;trillion solar years

====Current ''kalpa''====

A ''[[kalpa (time)|kalpa]]'' (day of [[Brahma]], 12 hours) lasts for 4.32{{nbsp}}billion years, where the current (''Shveta-Varaha Kalpa'') is the 1st of 30 in his 1st month of his 51st year:{{efn|name=Current time math}}
* Started in past:
: = 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 + ({{CURRENTYEAR}} + 3102 - 1)) + 4,320,000 * 27) + 1,728,000 * 7 + 306,720,000 * 6
: = {{val|{{sum
  |4320000
  |-432000
  |{{CURRENTYEAR}}
  |3102
  |-1
  |{{multiply|4,320,000|27|r=1|nosep=1}}
  |{{multiply|1,728,000|7|r=1|nosep=1}}
  |{{multiply|306,720,000|6|r=1|nosep=1}}
  }}|fmt=commas}} years
: ≈ {{round|{{multiply|{{sum
  |4320000
  |-432000
  |{{CURRENTYEAR}}
  |3102
  |-1
  |{{multiply|4,320,000|27|r=1|nosep=1}}
  |{{multiply|1,728,000|7|r=1|nosep=1}}
  |{{multiply|306,720,000|6|r=1|nosep=1}}
  }}|1/1,000,000,000|r=1|nosep=1}}|2}} billion years
* Ends in future:
: = 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 - ({{CURRENTYEAR}} + 3102 - 1)) + 4,320,000 * 43) + 1,728,000 * 8 + 306,720,000 * 7
: = {{val|{{sum
  |432000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  |{{multiply|4,320,000|43|r=1|nosep=1}}
  |{{multiply|1,728,000|8|r=1|nosep=1}}
  |{{multiply|306,720,000|7|r=1|nosep=1}}
  }}|fmt=commas}} years
: ≈ {{round|{{multiply|{{sum
  |432000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  |{{multiply|4,320,000|43|r=1|nosep=1}}
  |{{multiply|1,728,000|8|r=1|nosep=1}}
  |{{multiply|306,720,000|7|r=1|nosep=1}}
  }}|1/1,000,000,000|r=1|nosep=1}}|2}} billion years

====Current ''maha kalpa''====
A ''maha-kalpa'' (life of [[Brahma]]) lasts for 311.04{{nbsp}}trillion years:{{efn|name=Current time math}}
* Started in past:
: = 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 + ({{CURRENTYEAR}} + 3102 - 1)) + 4,320,000 * 27) + 1,728,000 * 7 + 306,720,000 * 6) + 4,320,000,000 * 36,000
: = {{val|1{{sum
  |4320000
  |-432000
  |{{CURRENTYEAR}}
  |3102
  |-1
  |{{multiply|4,320,000|27|r=1|nosep=1}}
  |{{multiply|1,728,000|7|r=1|nosep=1}}
  |{{multiply|306,720,000|6|r=1|nosep=1}}
  |{{multiply|4,320,000,000|36,000|r=1|nosep=1}}
  |-100000000000000
  }}|fmt=commas}} years <!-- hack: subtract 100 trillion and prepend 1 to display full number -->
: ≈ {{round|{{multiply|{{sum
  |4320000
  |-432000
  |{{CURRENTYEAR}}
  |3102
  |-1
  |{{multiply|4,320,000|27|r=1|nosep=1}}
  |{{multiply|1,728,000|7|r=1|nosep=1}}
  |{{multiply|306,720,000|6|r=1|nosep=1}}
  |{{multiply|4,320,000,000|36,000|r=1|nosep=1}}
  }}|1/1,000,000,000,000|r=1|nosep=1}}|2}} trillion years
* Ends in future:
: = 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 - ({{CURRENTYEAR}} + 3102 - 1)) + 4,320,000 * 43) + 1,728,000 * 8 + 306,720,000 * 7) + 4,320,000,000 * 35,999
: = {{val|1{{sum
  |432000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  |{{multiply|4,320,000|43|r=1|nosep=1}}
  |{{multiply|1,728,000|8|r=1|nosep=1}}
  |{{multiply|306,720,000|7|r=1|nosep=1}}
  |{{multiply|4,320,000,000|35,999|r=1|nosep=1}}
  |-100000000000000
  }}|fmt=commas}} years <!-- hack: subtract 100 trillion and prepend 1 to display full number -->
: ≈ {{round|{{multiply|{{sum
  |432000
  |-{{CURRENTYEAR}}
  |-3102
  |1
  |{{multiply|4,320,000|43|r=1|nosep=1}}
  |{{multiply|1,728,000|8|r=1|nosep=1}}
  |{{multiply|306,720,000|7|r=1|nosep=1}}
  |{{multiply|4,320,000,000|35,999|r=1|nosep=1}}
  }}|1/1,000,000,000,000|r=1|nosep=1}}|2}} trillion years

==Hindu texts==
===''Mahabharata''===
The ''[[Mahabharata]]'' (12.231.12–31) describes units of time from a wink of the eye (''nimesha'') up to the days (''[[kalpa (time)|kalpa]]'') and nights (''[[pralaya]]'') of [[Brahma]].<ref name="Dutt 1903"/>

{{quote box
 |align=center
 |salign=right
 |style=padding-bottom:0;
 |quote=
 <poem>
(12–13) The Rishis, measuring time, have given particular names to particular portions. Five and ten winks of the eye make what is called a Kashtha. Thirty Kashthas make what is called a Kala. Thirty Kalas, with the tenth part of a Kala, make a Muhurta. Thirty Muhurtas make up one day and night. Thirty days and nights form a month, and twelve months form a year.
</poem>

<poem>
(14) Persons well-read in mathematical science say that a year is made up of two solar motions, viz, the northern and the southern.
</poem>

<poem>
(15) The sun makes the day and the night for men. The night is for the sleep of all living creatures and the day is for work.
</poem>

<poem>
(16) A month of human beings is equal to a day and night of the departed manes. That division consists in this the light half of the month is their day which is for work, and the dark fortnight is their night for sleep.
</poem>

<poem>
(17) A year (of men) is equal to a day and night of the gods. This division consists in this the half year for which the sun travels from the vernal to the autumnal equinox is the day of the gods, and the half year for which the sun moves from the latter to the former is their night.
</poem>

<poem>
(18) Calculating by the days and nights of human beings about which I have told you I shall speak of the day and night of Brahman [(Brahma)] and his years also.
</poem>

<poem>
(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.
</poem>

<poem>
(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.
</poem>

<poem>
(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.
</poem>

<poem>
(29) The learned say that these twelve thousand celestial years form what is called a cycle. A thousand such cycles form a single day of Brahman [(Brahma)].
</poem>

<poem>
(30) The same is the duration of Brahman's [(Brahma's)] night. With the beginning of Brahman's [(Brahma's)] day the universe begins to come into being. During the period of universal dissolution the Creator sleeps in Yoga meditation. When the period of sleep expires, He awakes.
</poem>

<poem>
(31) What is Brahman's [(Brahma's)] day covers a thousand such cycles. His night also covers a thousand similar cycles. They who know this are said to know the day and the night.
</poem>
 |source=— ''[[Mahabharata]]'', Book 12 ([[Shanti Parva]]), Ch. 231<ref name="Dutt 1903">{{cite book |author-last=Dutt |author-first=Manmatha Nath |year=1903 |chapter=Ch. 231 (CCXXXI) |title=A Prose English Translation of The Mahabharata (Translated Literally from the Original Sanskrit text) |chapter-url=https://archive.org/details/in.ernet.dli.2015.142208/page/n272/mode/1up |volume=Book 12 (Shanti Parva) |location=Calcutta |publisher=Elysium Press |pages=350–351 (12.231.12–21, 29–31)}}</ref>{{efn|Chapter 224 (CCXXIV) in some sources: ''Mahabharata'' 12.224.}}
}}

===''Manusmriti''===
The ''[[Manusmriti]]'' ({{aka}} ''Laws of Manu''; 1.64–80) describes units of time from a twinkling of the eye (''nimesha'') up to the days (''[[kalpa (time)|kalpa]]'') and nights (''[[pralaya]]'') of [[Brahma]].<ref>{{cite book |author-last=Jones |author-first=Sir William |author-link=William Jones (philologist) |year=1807 |orig-year=1st ed. 1794 |chapter=The Laws of Menu, Son of Brahma - Chapter The First: On the Creation; with a Summary of the Contents |title=The Works of Sir William Jones in thirteen volumes. |chapter-url=https://archive.org/details/in.ernet.dli.2015.44659/page/n109/mode/1up |volume=VII |pages=101–104}}</ref><ref name="Bühler 1886"/><ref>{{cite book |author-last=Jha |author-first=Ganganath |author-link=Ganganath Jha |year=1999 |orig-year=1st ed. 1920 |chapter=Discourse I - Origin of the Work—Creation of the World—Summary of Contents of the Book. |title=Manusmriti with the Commentary of Medhatithi in Ten Volumes |url=https://www.wisdomlib.org/hinduism/book/manusmriti-with-the-commentary-of-medhatithi |via=Wisdom Library |volume=Adhyāya 1 |publisher=[[Motilal Banarsidass|Motilal Banarsidass Publishers Pvt. Ltd.]] |isbn=8120811550}}</ref>

{{quote box
 |align=center
 |salign=right
 |style=padding-bottom:0;
 |quote=
<poem>
{{lang|sa|निमेषा दश चाष्टौ च काष्ठा त्रिंशत् तु ताः कला ।
त्रिंशत् कला मुहूर्तः स्यादहोरात्रं तु तावतः ॥ ६४ ॥}}
{{transliteration|sa|nimeṣā daśa cāṣṭau ca kāṣṭhā triṃśat tu tāḥ kalā ।
triṃśat kalā muhūrtaḥ syādahorātraṃ tu tāvataḥ ॥ 64 ॥|italic=no}}
(64) Eighteen nimeshas (twinklings of the eye, are one kashtha), thirty kashthas one kala, thirty kalas one muhurta, and as many (muhurtas) one day and night.
</poem>

<poem>
{{lang|sa|अहोरात्रे विभजते सूर्यो मानुषदैविके ।
रात्रिः स्वप्नाय भूतानां चेष्टायै कर्मणामहः ॥ ६५ ॥}}
{{transliteration|sa|ahorātre vibhajate sūryo mānuṣadaivike ।
rātriḥ svapnāya bhūtānāṃ ceṣṭāyai karmaṇāmahaḥ ॥ 65 ॥|italic=no}}
(65) The sun divides days and nights, both human and divine, the night (being intended) for the repose of created beings and the day for exertion.
</poem>

<poem>
{{lang|sa|पित्र्ये रात्र्यहनी मासः प्रविभागस्तु पक्षयोः ।
कर्मचेष्टास्वहः कृष्णः शुक्लः स्वप्नाय शर्वरी ॥ ६६ ॥}}
{{transliteration|sa|pitrye rātryahanī māsaḥ pravibhāgastu pakṣayoḥ ।
karmaceṣṭāsvahaḥ kṛṣṇaḥ śuklaḥ svapnāya śarvarī ॥ 66 ॥|italic=no}}
(66) A month is a day and night of the manes, but the division is according to fortnights. The dark (fortnight) is their day for active exertion, the bright (fortnight) their night for sleep.
</poem>

<poem>
{{lang|sa|दैवे रात्र्यहनी वर्षं प्रविभागस्तयोः पुनः ।
अहस्तत्रोदगयनं रात्रिः स्याद् दक्षिणायनम् ॥ ६७ ॥}}
{{transliteration|sa|daive rātryahanī varṣaṃ pravibhāgastayoḥ punaḥ ।
ahastatrodagayanaṃ rātriḥ syād dakṣiṇāyanam ॥ 67 ॥|italic=no}}
(67) A year is a day and a night of the gods; their division is (as follows): the half year during which the sun progresses to the north will be the day, that during which it goes southwards the night.
</poem>

<poem>
{{lang|sa|ब्राह्मस्य तु क्षपाहस्य यत् प्रमाणं समासतः ।
एकैकशो युगानां तु क्रमशस्तन्निबोधत ॥ ६८ ॥}}
{{transliteration|sa|brāhmasya tu kṣapāhasya yat pramāṇaṃ samāsataḥ ।
ekaikaśo yugānāṃ tu kramaśastannibodhata ॥ 68 ॥|italic=no}}
(68) But hear now the brief (description of) the duration of a night and a day of Brahman [(Brahma)] and of the several ages (of the world, yuga) according to their order.
</poem>

<poem>
{{lang|sa|चत्वार्याहुः सहस्राणि वर्षाणां तत् कृतं युगम् ।
तस्य तावत्शती सन्ध्या सन्ध्यांशश्च तथाविधः ॥ ६९ ॥}}
{{transliteration|sa|catvāryāhuḥ sahasrāṇi varṣāṇāṃ tat kṛtaṃ yugam ।
tasya tāvatśatī sandhyā sandhyāṃśaśca tathāvidhaḥ ॥ 69 ॥|italic=no}}
(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.
</poem>

<poem>
{{lang|sa|इतरेषु ससन्ध्येषु ससन्ध्यांशेषु च त्रिषु ।
एकापायेन वर्तन्ते सहस्राणि शतानि च ॥ ७० ॥}}
{{transliteration|sa|itareṣu sasandhyeṣu sasandhyāṃśeṣu ca triṣu ।
ekāpāyena vartante sahasrāṇi śatāni ca ॥ 70 ॥|italic=no}}
(70) In the other three ages with their twilights preceding and following, the thousands and hundreds are diminished by one (in each).
</poem>

<poem>
{{lang|sa|यदेतत् परिसङ्ख्यातमादावेव चतुर्युगम् ।
एतद् द्वादशसाहस्रं देवानां युगमुच्यते ॥ ७१ ॥}}
{{transliteration|sa|yadetat parisaṅkhyātamādāveva caturyugam ।
etad dvādaśasāhasraṃ devānāṃ yugamucyate ॥ 71 ॥|italic=no}}
(71) These twelve thousand (years) which thus have been just mentioned as the total of four (human) ages, are called one age of the gods.
</poem>

<poem>
{{lang|sa|दैविकानां युगानां तु सहस्रं परिसङ्ख्यया ।
ब्राह्ममेकमहर्ज्ञेयं तावतीं रात्रिमेव च ॥ ७२ ॥}}
{{transliteration|sa|daivikānāṃ yugānāṃ tu sahasraṃ parisaṅkhyayā ।
brāhmamekamaharjñeyaṃ tāvatīṃ rātrimeva ca ॥ 72 ॥|italic=no}}
(72) But know that the sum of one thousand ages of the gods (makes) one day of Brahman [(Brahma)], and that his night has the same length.
</poem>

<poem>
{{lang|sa|तद् वै युगसहस्रान्तं ब्राह्मं पुण्यमहर्विदुः ।
रात्रिं च तावतीमेव तेऽहोरात्रविदो जनाः ॥ ७३ ॥}}
{{transliteration|sa|tad vai yugasahasrāntaṃ brāhmaṃ puṇyamaharviduḥ ।
rātriṃ ca tāvatīmeva te'horātravido janāḥ ॥ 73 ॥|italic=no}}
(73) Those (only, who) know that the holy day of Brahman [(Brahma)], indeed, ends after (the completion of) one thousand ages (of the gods) and that his night lasts as long, (are really) men acquainted with (the length of) days and nights.
</poem>

<poem>
{{lang|sa|यद् प्राग् द्वादशसाहस्रमुदितं दैविकं युगम् ।
तदेकसप्ततिगुणं मन्वन्तरमिहोच्यते ॥ ७९ ॥}}
{{transliteration|sa|yad prāg dvādaśasāhasramuditaṃ daivikaṃ yugam ।
tadekasaptatiguṇaṃ manvantaramihocyate ॥ 79 ॥|italic=no}}
(79) The before-mentioned age of the gods, (or) twelve thousand (of their years), being multiplied by seventy-one, (constitutes what) is here named the period of a Manu (Manvantara).
</poem>

<poem>
{{lang|sa|मन्वन्तराण्यसङ्ख्यानि सर्गः संहार एव च ।
क्रीडन्निवैतत् कुरुते परमेष्ठी पुनः पुनः ॥ ८० ॥}}
{{transliteration|sa|manvantarāṇyasaṅkhyāni sargaḥ saṃhāra eva ca ।
krīḍannivaitat kurute parameṣṭhī punaḥ punaḥ ॥ 80 ॥|italic=no}}
(80) The Manvantaras, the creations and destructions (of the world, are) numberless; sporting, as it were, Brahman [(Brahma)] repeats this again and again.
</poem>
 |source=— ''[[Manusmriti]]'', Ch. 1<ref name="Bühler 1886">{{cite book |author-last=Bühler |author-first=G. |author-link=Georg Bühler |year=1886 |chapter=Ch. 1, The Creation |editor-last=Müller |editor-first=F. Max |editor-link=Max Müller |title=The Laws of Manu: translated with extracts from seven commentaries |chapter-url=https://archive.org/details/lawsofman00manu/page/n162/mode/1up |series=[[Sacred Books of the East]] |volume=XXV |publisher=[[Oxford University Press]] |pages=19–20 (1.64–73), 22 (1.79–80)}}</ref>
}}

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).{{sfn|Olivelle|2005|pp=53–54}}

[[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 [[William Jones (philologist)|Sir William Jones]]'s translation, both based on Kulluka Bhatta's commentary. [[Medhātithi|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.<ref>{{cite book |author-last=Olivelle |author-first=Patrick |author-link=Patrick Olivelle |year=2005 |title=Manu's Code of Law |url=https://books.google.com/books?id=PnHo02RtONMC&pg=PA53 |publisher=[[Oxford University Press]] |pages=3, 241 (1.71) |isbn=0-19-517146-2}}</ref>

===''Surya Siddhanta''===
The ''[[Surya Siddhanta]]'' (1.10–21) describes units of time from a respiration (''prana''){{sfn|Burgess|1935|p=5|ps=: The manuscripts without commentary insert, as the first half of v. 11, the usual definition of the length of a respiration: "the time occupied in pronouncing ten long syllables is called a respiration." 10 long syllable (''gurvakshara'') = 1 respiration (''prana'', period of four seconds).}} up to the 100-year lifespan of [[Brahma]] (''maha-kalpa'').<ref name="Burgess 1935"/>

{{quote box
 |align=center
 |salign=right
 |style=padding-bottom:0;
 |quote=
<poem>
{{transliteration|sa|lokānām antakṛt kālaḥ kālo 'nyaḥ kalanātmakaḥ ।
sa dvidhā sthūlasūkṣmatvān mūrtaś cāmūrta ucyate ॥ 10 ॥|italic=no}}
(10) Time is the destroyer of the worlds; another Time has for its nature to bring to pass. This latter, according as it is gross or minute, is called by two names, real (murta) and unreal (amurta).
</poem>

<poem>
{{transliteration|sa|prāṇādiḥ kathito mūrtas truṭyādyo 'mūrtasaṃjñakaḥ ।
ṣaḍbhiḥ prāṇair vināḍī syāt tatṣaṣṭyā nāḍikā smṛtā ॥ 11 ॥|italic=no}}
(11) That which begins with respirations (prana) is called real; that which begins with atoms (truti) is called unreal. Six respirations make a vinadi, sixty of these a nadi;
</poem>

<poem>
{{transliteration|sa|nāḍīṣaṣṭyā tu nākṣatram ahorātraṃ prakīrtitam ।
tattriṃśatā bhaven māsaḥ sāvano 'rkodayais tathā ॥ 12 ॥|italic=no}}
(12) And sixty nadis make a sidereal day and night. Of thirty of these sidereal days is composed a month; a civil (savana) month consists of as many sunrises;
</poem>

<poem>
{{transliteration|sa|aindavas tithibhis tadvat saṃkrāntyā saura ucyate ।
māsair dvādaśabhir varṣaṃ divyaṃ tad aha ucyate ॥ 13 ॥|italic=no}}
(13) A lunar month, of as many lunar days (tithi); a solar (saura) month is determined by the entrance of the sun into a sign of the zodiac : twelve months make a year. This is called a day of the gods.
</poem>

<poem>
{{transliteration|sa|surāsurāṇām anyonyam ahorātraṃ viparyayāt ।
tatṣaṣṭiḥ ṣaḍguṇā divyaṃ varṣam āsuram eva ca ॥ 14 ॥|italic=no}}
(14) The day and night of the gods and of the demons are mutually opposed to one another. Six times sixty [360] of them are a year of the gods, and likewise of the demons.
</poem>

<poem>
{{transliteration|sa|taddvādaśasahasrāṇi caturyugam udāhṛtam ।
sūryābdasaṃkhyayā dvitrisāgarair ayutāhataiḥ ॥ 15 ॥|italic=no}}
(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
</poem>

<poem>
{{transliteration|sa|saṃdhyāsaṃdhyāṃśasahitaṃ vijñeyaṃ tac caturyugam ।
kṛtādīnāṃ vyavastheyaṃ dharmapādavyavasthayā ॥ 16 ॥|italic=no}}
(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:
</poem>

<poem>
{{transliteration|sa|yugasya daśamo bhāgaś catustridvyekasaṃguṇaḥ ।
kramāt kṛtayugādīnāṃ ṣaṣṭhāṃśaḥ saṃdhyayoḥ svakaḥ ॥ 17 ॥|italic=no}}
(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.
</poem>

<poem>
{{transliteration|sa|yugānāṃ saptatiḥ saikā manvantaram ihocyate ।
kṛtābdasaṃkhyās tasyānte saṃdhiḥ prokto jalaplavaḥ ॥ 18 ॥|italic=no}}
(18) One and seventy [71] Ages are styled here a Patriarchate (manvantara); at its end is said to be a twilight which has the number of years of a Golden Age, and which is a deluge.
</poem>

<poem>
{{transliteration|sa|sasaṃdhayas te manavaḥ kalpe jñeyāś caturdaśa ।
kṛtapramāṇaḥ kalpādau saṃdhiḥ pañcadaśaḥ smṛtaḥ ॥ 19 ॥|italic=no}}
(19) In an Æon (kalpa) are reckoned fourteen such Patriarchs (manu) with their respective twilights; at the commencement of the Æon is a fifteenth dawn, having the length of a Golden Age.
</poem>

<poem>
{{transliteration|sa|ittham yugasahasreṇa bhūtasaṃhārakārakaḥ ।
kalpo brāhmam ahaḥ proktaṃ śarvarī tasya tāvatī ॥ 20 ॥|italic=no}}
(20) The Æon, thus composed of a thousand Ages, and which brings about the destruction of all that exists, is styled a day of Brahma; his night is of the same length.
</poem>

<poem>
{{transliteration|sa|paramāyuḥ śataṃ tasya tayāhorātrasaṃkhyayā ।
āyuṣo 'rdhamitaṃ tasya śeṣakalpo 'yam ādimaḥ ॥ 21 ॥|italic=no}}
(21) His extreme age is a hundred, according to this valuation of a day and a night{{nbsp}}...
</poem>
 |source=— ''[[Surya Siddhanta]]'', Ch. 1<ref name="Burgess 1935">{{cite book |author-last=Burgess |author-first=Rev. Ebenezer |date=1935 |orig-date=1860 |chapter=Ch. 1: Of the Mean Motions of the Planets. |editor-last=Gangooly |editor-first=Phanindralal |title=Translation of the Surya-Siddhanta, A Text-Book of Hindu Astronomy; With notes and an appendix |chapter-url=https://archive.org/details/SuryaSiddhantaTranslation/page/n57/mode/1up |publisher=[[University of Calcutta]] |pages=5–12 (1.10–21)}}</ref>
}}

==See also==
{{Portal bar|Astronomy|History|Philosophy|Hinduism|Religion|Mythology}}
{{columns-list|
* [[Age of the universe]]
* [[Hindu astronomy]]
* [[Hindu calendar]]
* [[Hindu cosmology]]
* [[Indian mathematics]]
* [[Indian science and technology]]
* [[Indian weights and measures]]
* [[Jyotishya]]
* [[List of numbers in Hindu scriptures]]
* [[Tamil months]]
* [[Tamil units of measurement]]
* [[Time in India]]
* [[Universe]]
* [[Vedanga Jyotisha]]
* [[Vedas]]
* [[Yojana]]
}}

== Explanatory notes ==
{{Notelist|30em}}

==References==
{{reflist|30em}}

==External links==
* [https://legendofbharatbarsha.home.blog/2019/12/07/detailed-history-of-time/ Scientific Explanation of Hindu Time Units]
* [https://web.archive.org/web/20050320030038/http://www.thearchimedeandual.com/platonic/Eastern/surya_siddanta_commentary/surya_siddhanta.htm Surya Siddhanta, Chapter I with Commentary and Illustrations]

{{Navboxes|list=
{{Chronology}}
{{Indian astronomy}}
{{Brahmanda}}
{{Time in religion and mythology}}
{{systems of measurement}}
{{Time Topics}}
{{Time measurement and standards}}
}}

[[Category:Hindu astronomy|Units of time]]
[[Category:History of mathematics]]
[[Category:Vedic period]]
[[Category:Hindu philosophical concepts|Units of time]]
[[Category:Obsolete units of measurement]]
[[Category:Units of time]]
[[Category:Hindu calendar|Units of time]]
[[Category:Units of measurement by country]]
[[Category:Time in India]]
[[Category:Time in Nepal]]