Why India's Time Zones Are Off by a Half Hour

In the fourth century AD, Ujjain, Madhya Pradesh, reached its pinnacle of inventiveness and scientific advancement. The Surya Siddhanta, an ancient astronomical treatise, was considered to be the word of God by Ujjainis. Their greatest work counted time not in seconds, minutes, or hours, but in pra, which is the duration of one breath, or around four seconds. The second smallest unit of time, the pala, was made up of six pras, or 24 seconds, while one day was made up of 60 ghaliks. 

On September 7, 2012, Indian exhibitor Hardik sets up a display of wooden clocks at a booth at a fair in Amritsar.

The Ujjainis, who were among the first to propose that there is a 24-hour day, studied hundreds of people and found that the average heart rate was 15 beats per minute; this number is still used in modern medicine. 

It's reasonable to suppose that the ancient Ujjainis had no idea that many of their descendants would utilize clocks rather than their own bodies to tell time more than 1,600 years later. In addition, they could utilize a different tool entirely to determine the time at a far-off location.

The idea of time zones first appeared in the late 19th century, making it a relatively new occurrence. India, Sri Lanka, Nepal, Afghanistan, Myanmar, and a few other nations have deviated from such standards, despite the majority of the world having adopted Greenwich Meridian Time (GMT), which divides the globe into 24 time zones in one-hour increments with the central longitude going through Greenwich, England.