TheĀ  longitudinal extent of India is68 degree 7 min east and 97degree 25 mins east
its implicationsĀ  re 1- as the earth rotates from west to east the sun appears to move from east to west
2-for every 15degree of longitudinal extent there i a a corresponding difference of 1 hour as India east west longitudinal extent is nearly 29degree the time difference comes about 2 hours.
3-it is the longitudinal extent of India that 82degree 30 min east has been taken as standard meridian of India