There is a problem with Indian Standard Time because its trying to make a country that almost 3000km wide and function under one time zone.
Does it make complete sense?
India lies east of the Greenwich Meridian Line between 68°7′ towards west and 97°25′ towards east longitudes. Since, every 15° of the longitude correspond to one hour difference hence there is a time difference of almost 2 hours between western most and eastern most part of the country. Which means if someone living western most part of the Gujarat will experience sunrise at 6AM, the eastern most part of Arunachal Pradesh already seen at 4AM. And this is very inefficient in terms of making most of the day as possible.
The British understood this during colonial era and decided to split the country into two different time zones in 1884.
I.e. Bombay Time and Calcutta Time after two of the most important cities of that era.
But I’m 1904, when railway lines started linking up important places, a single time system had to be followed to avoide confusion.
Thay called it railway time and took a longitudinal reference that was somewhat midway between Bombay and Calcutta which turned out to Madras. But the different between Greenwich Mean Time (GMT) and Indian Railway Time was considered imperfect and there was a pressing need to make Indian Time ahead of GMT by exactly 5:30hours and corresponding longitude for that would be 82.5°E.
As this consequence people in cities like Guwahati spend an irrational number of daylight hours fast asleep and hours of darkness awake.
In 2006, the Planning Commission endorsed the idea of having two separate time zone but nothing much was done to put it in place.
A year later scientists from ISC in Bangalore said there were no need to split the country into two different time zone rather than reset IST 6 hours ahead of GMT instead of 5:30hours. This would result in India saving 2.7 billion units of electricity every year but that did not take of either.
There are other fears about multiple time zones like confusion and ambiguity in travel schedules but we only need to look at U.S. where airline and railways function perfectly with in 4 different time zone.
China which stretches 3500 end to end has only one time zone with aim of fostering national unity.
For now there does not seems to be any decision from Indian Government in solving the crisis of time between two parts of the country which means of our watches and clocks will keep ticking to IST for a long time to come.