section_path: Duration and structure
section_name: Duration and structure
paragraph_text: Duration and structure
  
  Hindu texts describe four yugas (world ages) in a Yuga Cycle, where, starting in order from the first age of Krita (Satya) Yuga, each yuga's length decreases by one-fourth (25%), giving proportions of 4:3:2:1. Each yuga is described as having a main period (a.k.a. yuga proper) preceded by its yuga-sandhyā (dawn) and followed by its yuga-sandhyāṃśa (dusk), where each twilight (dawn/dusk) lasts for one-tenth (10%) of its main period. Lengths are given in divine years (years of the gods), each lasting for 360 solar (human) years.
  
  Kali Yuga, the fourth age in a cycle, lasts for 432,000 years (1,200 divine years), where its main period lasts for 360,000 years (1,000 divine years) and its two twilights each last for 36,000 years (100 divine years). The current cycle's Kali Yuga, the present age, has the following dates based on it starting in 3102 BCE:
  
  Mahabharata, Book 12 (Shanti Parva), Ch. 231:
  
  (17) A year (of men) is equal to a day and night of the gods... (19) I shall, in their order, tell you the number of years that are for different purposes calculated differently, in the Krita, the Treta, the Dwapara, and the Kali yugas. (20) Four thousand celestial years is the duration of the first or Krita age. The morning of that cycle consists of four hundred years and its evening is of four hundred years. (21) Regarding the other cycles, the duration of each gradually decreases by a quarter in respect of both the principal period with the minor portion and the conjoining portion itself.
  
  Manusmriti, Ch. 1:
  
  (67) A year is a day and a night of the gods... (68) But hear now the brief (description of) the duration of a night and a day of Brahman and of the several ages (of the world, yuga) according to their order. (69) They declare that the Krita age (consists of) four thousand years (of the gods); the twilight preceding it consists of as many hundreds, and the twilight following it of the same number. (70) In the other three ages with their twilights preceding and following, the thousands and hundreds are diminished by one (in each).
  
  Surya Siddhanta, Ch. 1:
  
  (13)... twelve months make a year. This is called a day of the gods. (14)... Six times sixty of them are a year of the gods... (15) Twelve thousand of these divine years are denominated a Quadruple Age (caturyuga); of ten thousand times four hundred and thirty-two solar years (16) Is composed that Quadruple Age, with its dawn and twilight. The difference of the Golden and the other Ages, as measured by the difference in the number of the feet of Virtue in each, is as follows : (17) The tenth part of an Age, multiplied successively by four, three, two, and one, gives the length of the Golden and the other Ages, in order : the sixth part of each belongs to its dawn and twilight.