Question

while the sun rises earlier in the east, say nagaland and also sets earlier, how do the watch at kohima and New Delhi show the same time

Answer 1

because India follows a standard time whole across the country

Answer 2

If every place in a country had a different time depending on its longitude, then there would be a lot of confusion. Therefore, there is a standard time followed throughout the country . For India, this is Indian Standard Time (IST) which is 5 hours and 30 minutes ahead of UTC. For all places in India, this is the official time.