What is meant by Indian Standard Time? Why do we need a Standard Meridian for India?

As India is a large country through which a lot of meridians pass.

Therefore, one meridian passing through Naini near Allahabad, is considered as the Standard Meridian for India (82°5'E), and time at that meridian is termed as Indian Standard Time of the country.

Hence, this is the explanation for Indian Standard Time and it’s use