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. Time is described as eternal. Various fragments of time are described in the Vedas, Bhagavata Purana, Vishnu Purana, Mahabharata, Surya Siddhanta etc.
A Tithi or lunar day is defined as the time it takes for the longitudinalangle between the Moon and the Sun to increase by 12°. Tithis begin at varying times of day and vary in duration from approximately 19 to approximately 26 hours.
A Masa| or lunar month is divided into 2 paksha|s: the one between new moon and full moon is called gaura or or shukla paksha|; the one between full moon and new moon Kṛiṣhṇapaksha.
A Ritu | is 2 masa|.
An Ayana is 3 Ritu |s.
A year is two Ayanas.
Tropical metrics
Consists of the following:
A Yāma = of a day or night = Ghatis = Muhurtas = 3 Hour|s tely 24 hours.
Eight Yāmas make a full day
An Ahorātra'' is a tropical day
Cosmic metrics
The below table contains calculations of cosmic units of time and the time dilation experienced by different entities. Calculations use a traditional 360-day year and a standard 24-hour day for all entities.
Time dilation
affects the lifespan differently for humans, Pitris, Devas, Manus, and of Brahma. The division of a year for each is twelve 30-day months or 360 days, where a day is divided into a 12-hour dawn and 12-hour dusk. A 30-day month amounts to four 7-day weeks with an extra 8th day every two weeks. A traditional human year is measured by the sun's northern and southern 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. For this reason, a traditional 360-day year is equivalent to a modern ≈365.24-day solar or tropical year.
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, whose lifespan is equal to the duration of the manifested material elements, from which Brahma manifests his universe in Kalpa cycles:
51st year of 100
1st month of 12
1st Kalpa of 30
7th Manvantara of 14
28th of 71
4th Yuga of 4
A is followed by a of equal length. Each Kalpa is followed by a Pralaya of equal length. Preceding the first and following each Manvantara is a , each with a length of . 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 Dwapara Yuga ended with the "Saptarshi" constellation residing in the "Magha" constellation. The current Kali Yuga will end with the Sun, Moon and Jupiter residing in the "Pushya" sector.
Human
The history of humanity is divided up into four yugas —Krita Yuga, Treta Yuga, Dvapara Yuga and Kali Yuga—each with a 25% decline in dharmic practices and length, giving proportions of 4:3:2:1, 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 Chatur Yuga. Each yuga is divided into a main period and two Sandhis or — and or —where each Sandhi lasts for 10% of the main period. Lengths are given in divine years, where a divine year lasts for 360 solar years. A Yuga Cycle lasts for 4.32 million solar or 12,000 divine years.
Elapsed yuga
A Kali Yuga lasts for 432,000 years and is the 4th of 4 Yugas as well as the current Yuga, with that last for 36,000 years:
Yuga started 3102BCE in past:
' ends CE in:
' starts CE in:
Yuga ends CE in:
Elapsed chatur yuga
A Chatur Yuga lasts for 4.32million years, where the current is the 28th of 71:
Started BCE in past:
Ends CE in:
Pitri
The lifespan of the Pitris lasts for 100 of their years.
The lifespan of the Manus lasts for 100 of their years. Each Manu reigns over a period called a Manvantara, each lasting for 71. A total of 14 Manus reign successively in one Kalpa. Preceding the first and following each Manvantara is a ', each lasting the duration of a Satya Yuga. During each ', the earth is submerged in water.
1 day of Manu = 8,520 solar years
30 days of Manu = 255,600 solar years
12 months of Manu = 3,067,200 solar years
100 years of Manu = 306,720,000 solar years
Elapsed manvantara
A Manvantara lasts for 306.72million years, where the current is the 7th of 14:
Started in past:
Ends in:
Brahma
The lifespan of Brahma lasts for 100 of his years. His 12-hour day or Kalpa is followed by a 12-hour night or Pralaya of equal length. At the start of his 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. His 100-year life is called a, which is followed by a of equal duration, where the bases of the universe, Prakriti, is manifest at the start and unmanifest at the end of a.
A day of Brahma lasts for 4.32billion years, where the current is the 1st of 30 in his 1st month of his 51st year:
Started in past:
Ends in:
Elapsed maha kalpa
A life of Brahma lasts for 311.04trillion years:
Started in past:
Ends in:
Avatar
The Puranas describe Vishnu avatars that come during specific yugas, but may not occur in every Yuga Cycle. Rama appears at the end of Treta Yuga. According to Vayu Purana and Matsya Purana, Rama appeared in the 24thYuga Cycle. According to the Padma Purana, Rama also appeared in the 27th Yuga Cycle of the 6th Manvantara. Krishna's departure marked the end of Dvapara Yuga and the start of Kali Yuga according to Puranic sources. In the 28th Yuga Cycle, Krishna appeared as His original self, which only happens once in a Kalpa.
