The mainland of India extends between longitudes 68°7’E and 97°25’E. The East-West extension is 2933 km in length. The longitudinal extension shows that India is located in the Eastern Hemisphere and places can be located with reference to longitudes.
On account of the 30° longitudinal extension (97°25’–68°7’= 29°18’, approximately 30°) there is a time difference of 2 hours (30°×4 min = 120 mins or 2 hours) in local time between the Eastern and Western limits of India. However, a standard time (5 hours 30 min ahead of G.M.T.) is adopted according to the local time of the central meridian of the country, 82°30E.
