What is need of standard meridian of India Why has India selected an odd value of 8230longitude as SM?

The standard meridian of India, set at 82.5° E, serves as the reference for Indian Standard Time (IST), providing a uniform time across the country. India selected this specific meridian as it is geographically central, ensuring that the time difference between the eastern and western extremities of the country is minimized. The odd value of 82.5° E, which is not a whole number, was chosen to avoid conflicts with neighboring time zones and to better align with local solar time. This decision facilitates synchronization of time for various administrative, economic, and social activities across the diverse regions of India.