law: Standards of Weights and Measures Act, 1976 
  7. Base unit of time.
  
  - 
  (1) The base unit of
  
  time shall be the second.
  (2) The “second” is
  
  the duration of 9 192 631 770 periods of the radiation corresponding to the
  
  transition between the two hyperfine levels of the ground state of the caesium-
  
  133 atom.