If India adopts two time zones based on 75° E meridian for western India and 90° E meridian for eastern India, which one among the following states of eastern India will be benefited most ?

India currently follows a single Indian Standard Time (IST) based on the 82.5° E meridian [1]. However, the country spans nearly 30 degrees of longitude, from 68°7′E to 97°25′E [t3]. This causes the sun to rise and set approximately two hours earlier in the northeast compared to the west [c3][t1]. If a second time zone based on 90° E is adopted for eastern India, states located furthest east would benefit most by aligning their official working hours with natural daylight, thereby saving energy and increasing productivity [t1][t2]. Among the options, Manipur (approx. 94° E) is the easternmost state, followed by Assam (approx. 90°-95° E), West Bengal (approx. 88° E), and Bihar (approx. 85° E). Since Manipur is furthest from the current 82.5° E meridian and closest to the eastern extremity, it would experience the most significant correction in daylight synchronization.

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 18: Latitudes and Longitudes > Indian Standard Time > p. 245