Time in Indic cosmology is neither linear nor arbitrary—it is cyclical, hierarchical, and fractal. Spanning over 40 orders of magnitude, Indian chronometry bridges the sub-microsecond atomic interval of a Truṭi with the 311.04 trillion-year cosmic breath of Brahmā.
In traditional Vedic rituals, every seeker begins with the Saṅkalpa—a sacred formula reciting their exact spacetime coordinates in Brahmā's cosmic calendar:
Brahmā has completed 50 cosmic years (~155.52 trillion human years elapsed) and is in the 1st day of his 51st year.
One 12-hour daytime of Brahmā = 4.32 billion years. 6 Manvantaras have elapsed; we are in the 7th.
Governed by Manu Śrāddhadeva. 71 Mahā-Yugas per Manvantara; we are in the 28th Mahā-Yuga cycle.
Translate physical horizons (planetary lifespans, galactic orbits, light-travel distances, and biological pulses) into authentic Vedic dimensions—or explore what 1 Kalpa means in modern astrophysics:
1,000 Mahā-Yugas (14 Manvantaras + 15 Sandhis) = 1 single 12-hour daytime of the Creator Brahmā.
Explore every mathematical division defined in the Sūrya Siddhānta, Bhāgavata Purāṇa, and Viṣṇu Purāṇa:
| Unit Name | Sanskrit / Devanagari | Tier / Scale | Modern Duration | Mathematical Definition | Physical / Somatic Analogy | Scriptural Provenance |
|---|---|---|---|---|---|---|
| Truṭi | त्रुटि | Atomic Scale | ~29.62 nanoseconds (0.0296 µs) | Base indivisible unit; duration taken by light to pierce 3 atomic particles (Paramāṇus). | Light travels ~8.88 meters in one Truṭi. Comparable to the cycle time of a modern 33 MHz microprocessor. | Bhāgavata Purāṇa 3.11.4–5 |
| Vedha | वेध | Atomic Scale | ~2.96 microseconds (µs) | 100 Truṭis combine to form 1 Vedha. | Speed of ultrasonic echo transits in medical imaging; light travels ~888 meters. | Bhāgavata Purāṇa 3.11.5 |
| Lava | लव | Atomic Scale | ~8.89 microseconds (µs) | 3 Vedhas combine to form 1 Lava. | Duration of a high-speed camera spark discharge; frequency threshold of audible sound wave crests. | Bhāgavata Purāṇa 3.11.6 |
| Nimeṣa | निमेष | Atomic Scale | 0.288 seconds (288 milliseconds) | 3 Lavas combine to form 1 Nimeṣa (traditionally: the natural unhurried blink of a healthy human eye). | Matches the exact physiological blink rate of the human eye (150–300 ms). Also 1/3 of a standard heart cycle. | Bhāgavata Purāṇa 3.11.7 |
| Prāṇa (Asu) | प्राण (असु) | Biological & Somatic | 4.0 seconds | One normal calm biological respiration cycle (inhalation + exhalation); 6 Prāṇas = 1 Vināḍī (Pala). | 15 breaths per minute = 21,600 breaths per 24 hours (exactly matching the 21,600 arc-minutes of the 360° celestial zodiac). | Sūrya Siddhānta 1.11 |
| Kāṣṭhā | काष्ठा | Atomic Scale | 4.32 seconds | 15 Nimeṣas combine to form 1 Kāṣṭhā. | Duration of an Olympic 40-meter sprint; close to one complete breath cycle in relaxed Prāṇāyāma. | Bhāgavata Purāṇa 3.11.8 |
| Kalā | कला | Atomic Scale | 2.16 minutes (129.6 seconds) | 30 Kāṣṭhās combine to form 1 Kalā. | Duration of a traditional Vedic Sūkta recitation; approximately the time sunlight takes to traverse 38.8 million kilometers. | Bhāgavata Purāṇa 3.11.8 |
| Ghaṭikā (Nāḍī / Daṇḍa) | घटिका (नाडी) | Terrestrial Base Unit | 24.0 minutes | 30 Kalās (or 60 Vināḍīs) = 1/60th of a 24-hour day. Measured by a clepsydra water-bowl (Ghaṭī-Yantra). | The primary operational clock unit in classical India. Exactly 60 Ghaṭikās make up one terrestrial solar day. | Sūrya Siddhānta 1.11–12 |
| Muhūrta | मुहूर्त | Terrestrial Base Unit | 48.0 minutes | 2 Ghaṭikās (1/30th of an Ahorātra). The standard unit for astrological, contemplative, and ritual timing. | The famous Brāhma Muhūrta is the penultimate 48-minute window before sunrise (approx 4:24 AM to 5:12 AM). | Bhāgavata Purāṇa 3.11.9 |
| Ahorātra (Divasa) | अहोरात्र (दिवस) | Human Cycle | 24.0 hours (1 Solar Day) | 30 Muhūrtas (Day + Night) determined by one complete axial rotation of the Earth relative to the Sun. | Contains 60 Ghaṭikās, 30 Muhūrtas, and 21,600 Prāṇas (human breaths). | Sūrya Siddhānta 1.12 |
| Pakṣa | पक्ष | Human Cycle | ~14.76 days (1 Fortnight) | 15 lunar Tithis. Divided into Śukla Pakṣa (bright waxing fortnight) and Kṛṣṇa Pakṣa (dark waning fortnight). | One Pakṣa equals one half of the Moon’s synodic orbit; corresponds to the tides and biological lunar rhythms. | Bhāgavata Purāṇa 3.11.10 |
| Māsa | मास | Human Cycle | ~29.53 days (1 Lunar Month) | 2 Pakṣas (30 Tithis). 1 Lunar Month = 1 Day-and-Night of the Pitṛs (Ancestors). | Śukla Pakṣa is daytime for the lunar ancestors (Pitṛs); Kṛṣṇa Pakṣa is their night for sleep. | Sūrya Siddhānta 1.13 |
| Ṛtu | ऋतु | Human Cycle | ~2.0 months (~60 days) | 2 Solar Months. The Indian calendar recognizes 6 distinct seasons: Vasanta, Grīṣma, Varṣā, Śarad, Hemanta, Śiśira. | Governs Āyurvedic seasonal regimens (Ṛtucaryā), agricultural sowing, and classical Sanskrit poetics. | Suśruta Saṁhitā, Sūtra 6 |
| Ayana | अयन | Human Cycle | 6.0 months (Solstice cycle) | 3 Ṛtus (6 months). Uttarāyaṇa (northern solar progression, Makar to Mithun) and Dakṣiṇāyana (southern descent). | Uttarāyaṇa represents daytime for the celestial Devas; Dakṣiṇāyana is nighttime for the Devas. | Sūrya Siddhānta 1.13–14 |
| Varṣa (Saṁvatsara) | वर्ष (संवत्सर) | Human Cycle | 1.0 Solar Year (365.25 days) | 2 Ayanas (1 Human Solar Year). Equals exactly one complete 24-hour Day-and-Night of the Devas. | 1 human year = 1 Deva-Ahorātra. Uttarāyaṇa (6 mo) is the day; Dakṣiṇāyana (6 mo) is the night. | Sūrya Siddhānta 1.13–14 |
| Deva-Varṣa (Divine Year) | दिव्य वर्ष (देव वर्ष) | Cosmic Cycle | 360 Human Solar Years | 360 Human Years = 360 Divine Days = 1 Year of the Gods. | Roughly 14 human generations. Long enough to encompass the rise and fall of whole earthly dynasties. | Sūrya Siddhānta 1.14 |
| Kali Yuga (Iron Age) | कलियुग | Cosmic Cycle | 432,000 Human Years | 1,200 Divine Years (100 dawn + 1,000 main + 100 dusk). Dharma stands on 1 leg out of 4 (truthfulness). | Began Feb 18, 3102 BCE at Lord Kṛṣṇa’s departure. In 2026 CE, exactly 5,127 years have elapsed (~1.19%). | Sūrya Siddhānta 1.15–17 |
| Dvāpara Yuga (Bronze Age) | द्वापरयुग | Cosmic Cycle | 864,000 Human Years | 2,400 Divine Years (2x Kali duration). Dharma stands on 2 legs (Yajña & Tapas). Age of Mahābhārata. | Exactly twice the length of Kali Yuga. Human lifespans are recorded as up to 1,000 years. | Sūrya Siddhānta 1.16 |
| Tretā Yuga (Silver Age) | त्रेतायुग | Cosmic Cycle | 1,296,000 Human Years | 3,600 Divine Years (3x Kali duration). Dharma stands on 3 legs. Age of Śrī Rāma and Rāmāyaṇa. | Three times the length of Kali Yuga; spans earlier human evolution and Pleistocene transitions. | Sūrya Siddhānta 1.16 |
| Satya (Kṛta) Yuga (Golden Age) | सत्ययुग (कृतयुग) | Cosmic Cycle | 1,728,000 Human Years | 4,800 Divine Years (4x Kali duration). Dharma stands fully on all 4 legs (Tapas, Śauca, Dayā, Satya). | Four times the length of Kali Yuga. Consciousness is naturally established in truth and direct contemplation. | Sūrya Siddhānta 1.15–17 |
| Mahā-Yuga (Catur-Yuga) | महायुग (चतुर्युग) | Cosmic Cycle | 4.32 Million Human Years | 12,000 Divine Years. Complete cycle of 4 Yugas in fixed ratio 4:3:2:1 (Satya + Tretā + Dvāpara + Kali). | Corresponds roughly to astronomical Milankovitch orbital eccentricity and geomagnetic reversal cycles. | Sūrya Siddhānta 1.17 |
| Manvantara | मन्वन्तर | Cosmic Epoch | 306.72 Million Human Years | 71 Mahā-Yugas governed by one Manu (the cosmic progenitor) and his distinct Saptarṣis and Indra. | Comparable to the Sun’s orbital period around the galactic center of the Milky Way (~230 million years). | Sūrya Siddhānta 1.18 |
| Sandhyā-Kāla (Deluge Junction) | सन्ध्या-काल (सन्धि) | Cosmic Epoch | 1.728 Million Human Years | Transitional period lasting 1 Kṛta-Yuga (1.728M years) between two Manvantaras, marked by cosmic deluge (Pralaya). | 15 Sandhis punctuate the 14 Manvantaras of a Kalpa, ensuring pristine renewal between cosmic lineages. | Viṣṇu Purāṇa 1.3.19–21 |
| Kalpa (Day of Brahmā) | कल्प (ब्रह्म-दिन) | Cosmic Era | 4.32 Billion Human Years | 1,000 Mahā-Yugas (14 Manvantaras + 15 Sandhis) = 1 single 12-hour daytime of the Creator Brahmā. | Astonishingly close to the scientifically calculated age of the Earth and Solar System (~4.54 billion years)! | Sūrya Siddhānta 1.19–20 |
| Brahmā-Ahorātra (Day + Night) | ब्रह्म-अहोरात्र | Cosmic Era | 8.64 Billion Human Years | 1 Day of creation (Kalpa = 4.32B yr) + 1 Night of cosmic dissolution (Naimittika Pralaya = 4.32B yr). | Carl Sagan remarked: "The only religion in which the time scales correspond to those of modern scientific cosmology." | Bhagavad Gītā 8.17, Sūrya Siddhānta 1.20 |
| Brahmā-Varṣa (Year of Brahmā) | ब्रह्म-वर्ष | Cosmic Span | 3.1104 Trillion Human Years | 360 Brahmā Days and Nights. During the day universe manifests; during the night it enters contemplative slumber. | Over 225 times the modern estimated age of our observable universe (13.8 billion years). | Sūrya Siddhānta 1.21 |
| Mahā-Kalpa (Life of Brahmā) | महाकल्प (ब्रह्मायुः) | Ultimate Span | 311.04 Trillion Human Years | 100 Divine Years of Brahmā (Para). At its end comes Prākṛtika Pralaya where even the elements dissolve into unmanifest Prakṛti. | The absolute lifespan of a cosmic cycle before complete reabsorption into the Supreme Absolute (Parabrahman). | Sūrya Siddhānta 1.21, Bhāgavata Purāṇa 3.11.33–38 |
Base indivisible unit; duration taken by light to pierce 3 atomic particles (Paramāṇus).
Light travels ~8.88 meters in one Truṭi. Comparable to the cycle time of a modern 33 MHz microprocessor.
Bhāgavata Purāṇa 3.11.4–5
~29.62 nanoseconds (0.0296 µs)
100 Truṭis combine to form 1 Vedha.
Speed of ultrasonic echo transits in medical imaging; light travels ~888 meters.
Bhāgavata Purāṇa 3.11.5
~2.96 microseconds (µs)
3 Vedhas combine to form 1 Lava.
Duration of a high-speed camera spark discharge; frequency threshold of audible sound wave crests.
Bhāgavata Purāṇa 3.11.6
~8.89 microseconds (µs)
3 Lavas combine to form 1 Nimeṣa (traditionally: the natural unhurried blink of a healthy human eye).
Matches the exact physiological blink rate of the human eye (150–300 ms). Also 1/3 of a standard heart cycle.
Bhāgavata Purāṇa 3.11.7
0.288 seconds (288 milliseconds)
One normal calm biological respiration cycle (inhalation + exhalation); 6 Prāṇas = 1 Vināḍī (Pala).
15 breaths per minute = 21,600 breaths per 24 hours (exactly matching the 21,600 arc-minutes of the 360° celestial zodiac).
Sūrya Siddhānta 1.11
4.0 seconds
15 Nimeṣas combine to form 1 Kāṣṭhā.
Duration of an Olympic 40-meter sprint; close to one complete breath cycle in relaxed Prāṇāyāma.
Bhāgavata Purāṇa 3.11.8
4.32 seconds
30 Kāṣṭhās combine to form 1 Kalā.
Duration of a traditional Vedic Sūkta recitation; approximately the time sunlight takes to traverse 38.8 million kilometers.
Bhāgavata Purāṇa 3.11.8
2.16 minutes (129.6 seconds)
30 Kalās (or 60 Vināḍīs) = 1/60th of a 24-hour day. Measured by a clepsydra water-bowl (Ghaṭī-Yantra).
The primary operational clock unit in classical India. Exactly 60 Ghaṭikās make up one terrestrial solar day.
Sūrya Siddhānta 1.11–12
24.0 minutes
2 Ghaṭikās (1/30th of an Ahorātra). The standard unit for astrological, contemplative, and ritual timing.
The famous Brāhma Muhūrta is the penultimate 48-minute window before sunrise (approx 4:24 AM to 5:12 AM).
Bhāgavata Purāṇa 3.11.9
48.0 minutes
30 Muhūrtas (Day + Night) determined by one complete axial rotation of the Earth relative to the Sun.
Contains 60 Ghaṭikās, 30 Muhūrtas, and 21,600 Prāṇas (human breaths).
Sūrya Siddhānta 1.12
24.0 hours (1 Solar Day)
15 lunar Tithis. Divided into Śukla Pakṣa (bright waxing fortnight) and Kṛṣṇa Pakṣa (dark waning fortnight).
One Pakṣa equals one half of the Moon’s synodic orbit; corresponds to the tides and biological lunar rhythms.
Bhāgavata Purāṇa 3.11.10
~14.76 days (1 Fortnight)
2 Pakṣas (30 Tithis). 1 Lunar Month = 1 Day-and-Night of the Pitṛs (Ancestors).
Śukla Pakṣa is daytime for the lunar ancestors (Pitṛs); Kṛṣṇa Pakṣa is their night for sleep.
Sūrya Siddhānta 1.13
~29.53 days (1 Lunar Month)
2 Solar Months. The Indian calendar recognizes 6 distinct seasons: Vasanta, Grīṣma, Varṣā, Śarad, Hemanta, Śiśira.
Governs Āyurvedic seasonal regimens (Ṛtucaryā), agricultural sowing, and classical Sanskrit poetics.
Suśruta Saṁhitā, Sūtra 6
~2.0 months (~60 days)
3 Ṛtus (6 months). Uttarāyaṇa (northern solar progression, Makar to Mithun) and Dakṣiṇāyana (southern descent).
Uttarāyaṇa represents daytime for the celestial Devas; Dakṣiṇāyana is nighttime for the Devas.
Sūrya Siddhānta 1.13–14
6.0 months (Solstice cycle)
2 Ayanas (1 Human Solar Year). Equals exactly one complete 24-hour Day-and-Night of the Devas.
1 human year = 1 Deva-Ahorātra. Uttarāyaṇa (6 mo) is the day; Dakṣiṇāyana (6 mo) is the night.
Sūrya Siddhānta 1.13–14
1.0 Solar Year (365.25 days)
360 Human Years = 360 Divine Days = 1 Year of the Gods.
Roughly 14 human generations. Long enough to encompass the rise and fall of whole earthly dynasties.
Sūrya Siddhānta 1.14
360 Human Solar Years
1,200 Divine Years (100 dawn + 1,000 main + 100 dusk). Dharma stands on 1 leg out of 4 (truthfulness).
Began Feb 18, 3102 BCE at Lord Kṛṣṇa’s departure. In 2026 CE, exactly 5,127 years have elapsed (~1.19%).
Sūrya Siddhānta 1.15–17
432,000 Human Years
2,400 Divine Years (2x Kali duration). Dharma stands on 2 legs (Yajña & Tapas). Age of Mahābhārata.
Exactly twice the length of Kali Yuga. Human lifespans are recorded as up to 1,000 years.
Sūrya Siddhānta 1.16
864,000 Human Years
3,600 Divine Years (3x Kali duration). Dharma stands on 3 legs. Age of Śrī Rāma and Rāmāyaṇa.
Three times the length of Kali Yuga; spans earlier human evolution and Pleistocene transitions.
Sūrya Siddhānta 1.16
1,296,000 Human Years
4,800 Divine Years (4x Kali duration). Dharma stands fully on all 4 legs (Tapas, Śauca, Dayā, Satya).
Four times the length of Kali Yuga. Consciousness is naturally established in truth and direct contemplation.
Sūrya Siddhānta 1.15–17
1,728,000 Human Years
12,000 Divine Years. Complete cycle of 4 Yugas in fixed ratio 4:3:2:1 (Satya + Tretā + Dvāpara + Kali).
Corresponds roughly to astronomical Milankovitch orbital eccentricity and geomagnetic reversal cycles.
Sūrya Siddhānta 1.17
4.32 Million Human Years
71 Mahā-Yugas governed by one Manu (the cosmic progenitor) and his distinct Saptarṣis and Indra.
Comparable to the Sun’s orbital period around the galactic center of the Milky Way (~230 million years).
Sūrya Siddhānta 1.18
306.72 Million Human Years
Transitional period lasting 1 Kṛta-Yuga (1.728M years) between two Manvantaras, marked by cosmic deluge (Pralaya).
15 Sandhis punctuate the 14 Manvantaras of a Kalpa, ensuring pristine renewal between cosmic lineages.
Viṣṇu Purāṇa 1.3.19–21
1.728 Million Human Years
1,000 Mahā-Yugas (14 Manvantaras + 15 Sandhis) = 1 single 12-hour daytime of the Creator Brahmā.
Astonishingly close to the scientifically calculated age of the Earth and Solar System (~4.54 billion years)!
Sūrya Siddhānta 1.19–20
4.32 Billion Human Years
1 Day of creation (Kalpa = 4.32B yr) + 1 Night of cosmic dissolution (Naimittika Pralaya = 4.32B yr).
Carl Sagan remarked: "The only religion in which the time scales correspond to those of modern scientific cosmology."
Bhagavad Gītā 8.17, Sūrya Siddhānta 1.20
8.64 Billion Human Years
360 Brahmā Days and Nights. During the day universe manifests; during the night it enters contemplative slumber.
Over 225 times the modern estimated age of our observable universe (13.8 billion years).
Sūrya Siddhānta 1.21
3.1104 Trillion Human Years
100 Divine Years of Brahmā (Para). At its end comes Prākṛtika Pralaya where even the elements dissolve into unmanifest Prakṛti.
The absolute lifespan of a cosmic cycle before complete reabsorption into the Supreme Absolute (Parabrahman).
Sūrya Siddhānta 1.21, Bhāgavata Purāṇa 3.11.33–38
311.04 Trillion Human Years
"The Hindu religion is the only one of the world's great faiths dedicated to the idea that the Cosmos itself undergoes an immense, indeed an infinite, number of deaths and rebirths. It is the only religion in which the time scales correspond, to those of modern scientific cosmology. Its cycles run from our ordinary day and night to a day and night of Brahma, 8.64 billion years long. Longer than the age of the Earth or the Sun and about half the time since the Big Bang. And there are much longer time scales still."
The mathematical values and hierarchies presented in this explorer are preserved in ancient astronomical and philosophical treatises:
The foundational astronomical treatise establishing the division of time from the breath (Prāṇa) to divine years, the 4:3:2:1 Yuga proportions, Manvantaras, and the 4.32 billion-year Kalpa day.
Exhaustive philosophical exposition of atomic time (Paramāṇu-Kāla) detailing the microscopic divisions: Truṭi, Vedha, Lava, Nimeṣa, Kāṣṭhā, Kalā, Ghaṭikā, and Muhūrta.
Detailed computation of the 14 Manvantaras, the 15 intervening Sandhyās (deluge periods), and the four types of cosmic dissolution (Nitya, Naimittika, Prākṛtika, and Ātyantika Pralaya).
"Sahasra-yuga-paryantam ahar yad brahmaṇo viduḥ / rātriṁ yuga-sahasrāntāṁ te 'ho-rātra-vido janāḥ" — Declaring that those who comprehend the 1,000-Yuga day and night of Brahmā truly perceive the nature of time.