yugas The concept of kāla or time as evolved by the Hindu scriptures from the smallest unit to colossal limits is, to say the least, mind-boggling. Nimeṣa, the time taken for winking the eyelids once, is taken as the smallest unit. The biggest unit, for the purpose of expounding the concept of yuga, can be taken as one day of Brahmā, the four-faced creator. It is called kalpa. In terms of human years it is 4.32 billion (4.32 x 109) years. This kalpa includes 1000 mahāyugas. Each mahāyuga—also called caturyuga— consists of the four well-known yugas: Kṛta, Tretā, Dvāpara and Kali. The following table gives an idea of these four yugas in terms of divine and human years, the divine year being 360 times the human year: Divine Years Human Years Kṛtayuga 4800 17,28,000 Tretāyuga 3600 12,96,000 Dvāparayuga 2400 8,64,000 Kaliyuga 1200 4,32,000 Each of these yugas is preceded by a short period called sandhyā and followed by another, called sandhyāṅiśa. Thus, the Kṛtayuga is preceded by 400 divine years (sandhyā) and followed by another 400 divine years (sandhyāṅiśa). The figures for the other three are 300 + 300; 200 + 200; 100 + 100. The descriptions given so far are based on the ones commonly found in the epics and the purāṇas (vide Visnupurāna 1.3; 6.3). However, the meaning and concept seem to have undergone quite a few changes in course of time. In the Vedāñga- jyautisa (verse 5) it is a duration of five years. In the Rgveda (3.26.3) it means just a day or a very short period. In other places, the names Kṛta and so on have been used to indicate a number got by the throw of dice. (vide Chāndogya Upanisad 4.1.4.) See also dvāparayuga, kāla, kali- YUGA, KALPA, KRTAYUGA, MANVANTARA, TRETĀYUGA.