KĀLAMĀNA (Calculating time). In ancient days in India time was calculated in the following manner. Time taken (needed) to pierce a leaf with a needle--Alpakāla 30 Alpakālas--1 Truṭi 30 Truṭis--1 Kalā 30 Kalās--1 Kāṣṭhā 30 Kāṣṭhās--1 Nimiṣa (mātrā) 4 Nimiṣas--1 Gaṇita 10 Gaṇitas--1 Neṭuvīrpu (time for a deep sigh) 6 Neṭuvīrpus--1 Vināzhikā 6 Vināzhikās--1 Ghaṭikā 60 Ghaṭikās--1 Day (Ahorātra) 15 Ahorātras--1 Pakṣa (Fortnight) 2 Pakṣas--1 Cāndramāsa (A day for the Pitṛs) 2 Māsas (months)--1 Ṛtu. 6 Ṛtus--1 year for men (A day for the Devas) 300 Years (Men's)--1 Divyavarṣa (Divine year) 4800 Divyavarṣas--1 Kṛtayuga 3600 Divyavarṣas--1 Tretāyuga 2400 Divyavarṣas--1 Dvāparayuga 1200 Divyavarṣas--1 Kaliyuga 12000 Divyavarṣas--1 Caturyuga 71 Caturyugas--1 Manvantara 14 Manvantaras--1 Pralaya (Kalpa) 1 Pralaya--Brahmā's one day.
[Bhāgavata Tṛtīya skandha] 7(1/2) Nāzhikās (Ghaṭikās)--1 Yāma 4 Yāmas--1 day time 8 Yāmas--1 day (day and night).
[Devī Bhāgavata, 9th Skandha] . The ‘Kālamāna’ according to the Viṣṇu Purāṇa differs in certain respects from the calculations given above. Chapter 3, Part 1 of Viṣṇu Purāṇa says:-- Fifteen Nimiṣas make one Kāṣṭhā. Thirty Kāṣṭhās make one Kalā and thirty Kalās make one Muhūrta. Thirty Muhūrtas make one day (man's) and thirty such days, divided into two fortnights form a Māsa (month). Six months form an Ayana; there are two ayanas called Dakṣiṇa and Uttara. Dakṣiṇāyana is night, and Uttarāyaṇa is day for the Devas. 12,000 Divyavarṣas--Deva varṣas--form a Caturyuga consisting of the Kṛta--Tretā--Dvāpara and Kali yugas, consisting respectively of 4000, 3000, 2000 and 1000 Divyavarṣas. Before the commencement and after the end of every one of the above four yugas there is an interval respectively of 400, 300, 200, and 100 years. The interval before the commencement is called Sandhyā and that at the end is called Sandhyāṁśa. The period between Sandhyā and Sandhhyāṁśa is called Kṛta yuga etc. One thousand Caturyugas form one day for Brahmā, and it (Brahmā's one day) has 14 Manus. Again, Chapter 8, Part 2 of the Viṣṇu Purāṇa has the following to say about Kālamāna. Fifteen nimisas make one Kāṣṭhā, thirty Kāṣṭhās one Kalā, thirty Kalās one muhūrta and thirty muhūrtas one day and night. Day is long or short according to the length or shortness of parts of the day, like morning, noon and evening. Despite the above variation evening or dusk time is always (2 nāzhikās) the same. The three muhūrtas from the sun's ardhodaya (when half of the sun has arisen) is called Prātaḥkāla, (morning) and it is (1/5)th of day time. The three muhūrtas following are known as saṁgava. Madhyāhna (noon) is the three muhūrtas after saṁgava. The time after madhyāhna is aparāhna (afternoon). Aparāhna lasts for three muhūrtas. The time after this is dusk. Thus, a day-time of fifteen muhūrtas is divided into five parts of three muhūrtas each. On Viṣuvat day the day will have full fifteen muhūrtas. Then during Uttarāyaṇa and Dakṣiṇāyana the day will be longer or shorter. During Uttarāyaṇa the day will be longer than night, and during Dakṣiṇāyana vice versa. Viṣuvat occurs when the sun enters the Tulā (Libra) and Meṣa (Aries) houses. Dakṣiṇāyana is when the sun enters Cancer, and Uttarāyana when it enters Capricorn. Fifteen days and nights constitute a Pakṣa (fortnight) and two Pakṣas one month. Two solar months constitute a Ṛtu (season), three ṛtus one ayana and two ayanas one year. Since there are four kinds of months, i.e. Saura, Sāvana, Cāndra and Nākṣatra, years are considered to be of five different kinds. The first is called Saṁvatsara; the second parivatsara; the third iḍvatsara; the fourth, anuvatsara and the fifth, vatsara. This period of five years is called a yuga. In a yuga of five years there are 60 saura months, 61 sāvana months, 62 Cāndra months and 67 nākṣatra months. At the beginning of the sixth year the sun and moon meet in the same house and that period of five years also is called yuga. (Śrīdharīyam).