law: Negotiable Instruments Act, 1881 
  22. "Maturity" 
  The maturity of a promissory note or bill of exchange is the
  
  date at which it falls due.
  Days of grace: Every promissory note or bill of exchange which
  
  is not expressed to be payable on demand, at sight or on presentment is at
  
  maturity on the third day after the day on which it is expressed to be payable.