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.
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.)
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:
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.
| Unit | Definition | Equivalence (Approx.) | |
|---|---|---|---|
| Truti | त्रुटि | 0.031 µs | |
| Renu | रेणु | 60 Truti | 1.86 µs |
| Lava | लव | 60 Renu | 0.11 ms |
| Līkṣaka | लीक्षक | 60 Lava | 6.696 ms |
| Lipta | लिप्ता | 60 Leekshaka | 0.401 s |
| Vipala | विपल | ||
| Pala | पल | 60 Lipta | 24.1056 s |
| Vighaṭi | विघटि | ||
| Vinādī | विनाडी | ||
| Ghaṭi | घटि | 60 Vighaṭi | 24 min |
| Nādī | नाडी | ||
| Danda | दण्ड | ||
| Muhūrta | मुहूर्त | 2 Ghaṭi | 48 min |
| Nakṣatra Ahorātram (Sidereal Day) | नक्षत्र अहोरात्रम् | 60 Ghaṭī | 24 h |
| 30 Muhūrta | 24 h | ||
| Unit | Definition | Equivalence (Approx.) |
|---|---|---|
| Truti | 35.5 µs | |
| Tatpara | 100 Truti | 3.55 ms |
| Nimesha | 30 Tatpara | 106.7 ms |
| Kāṣṭhā | 30 Nimesha | 3.2 s |
| Kalā | 30 Kāṣṭhā | 1.6 min |
| Muhūrta | 30 Kalā | 48 min |
| Nakṣatra Ahorātram (Sidereal Day) | 30 Muhūrta | 24 h |
Small units of time used in the Vedas
| Unit | Definition | Equivalence (Approx.) |
|---|---|---|
| Paramāṇu | 26.3 µs | |
| Aṇu | 2 Paramāṇu | 57.7 µs |
| Trasareṇu | 3 Aṇu | 158 µs |
| Truṭi | 3 Trasareṇu | 474 µs |
| Vedha | 100 Truṭi | 47.4 ms |
| Lava | 3 Vedha | 0.14 s |
| Nimeṣa | 3 Lava | 0.43 s |
| Kṣaṇa | 3 Nimesha | 1.28 s |
| Kāṣṭhā | 5 Kṣaṇa | 6.4 s |
| Laghu | 15 Kāṣṭhā | 1.6 min |
| Danda | 15 Laghu | 24 min |
| Muhūrta | 2 Danda | 48 min |
| Ahorātram (Day) | 30 Muhūrta | 24 h |
| Masa (Month) | 30 Ahorātram | 30 days |
| Ritu (Season) | 2 Masa | 2 months |
| Ayana | 3 Rutu | 6 months |
| Samvatsara (Year) | 2 Ayana | 360 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.)
| Name | Definition | Equivalence | |
|---|---|---|---|
| Yama | याम | ¼ th of a day (light) or night | 3 hours |
| Sāvana Ahorātram | सावन अहोरात्रम् | 8 Yamas | 1 Solar day |
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]
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:
| 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.
- A 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.)
- A 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).
