Scottish-born Canadian Sir Sandford Fleming proposed a worldwide system of time zones in 1879.Eventually in 1884 International meridian conference adopted a 24 hour day.Countries across the world keep different times because of Earth’s rotation and revolution around the Sun.As Earth turns by 15° around its axis, time changes by one hour; a 360º-degree rotation yields 24 hours.As a result, the world is divided into 24 time zones shifted by one hour each.
What is Time Zone?
- A time zone is a region of the globe that observes a uniform standard time for legal, commercial, and social purposes.
- Time zones tend to follow the boundaries of countries and their subdivisions because it is convenient for areas in close commercial or other communication to keep the same time.
- This time zone is used to save daylight. Hence, zero degrees longitude, which is also called prime meridian chosen as International Standard Time because it is based on the Earth’s rotation (which is irregular) it actually follows a fictitious Mean Sun that moves at a uniform speed along the equator.
Indian Standard Time
- IST is based on longitude 82.5°, which passes through Mirzapur, near Allahabad in Uttar Pradesh.
- It is 5 hours 30 minutes ahead of Greenwich Mean Time (GMT), now called the Universal Coordinated Time (UTC).
- Keeper of the time in India is the CSIR-National Physical Laboratory (NPL), New Delhi, which records time using five caesium atomic clocks.
History of Time Zones in India
- India used to have two time zones, Bombay Time and Calcutta Time, first established in 1884 during the British Raj.
- Indian Standard Time is an anachronism like many systems that were inherited from the British.
- It was in 1906 that India had a single IST running through center of country.
- There was a one-hour-nine-minutes time difference between Kolkata and Mumbai. Yet, today these cities, which are 1,650km apart, share the same time.
- Tea estates of Assam, where the concept of ‘bagaan time’ (estate time) exists, is there a provision for a separate time zone inside India. Bagaan time is one hour ahead of IST.
Why India need two time zones?
- Indian Standard Time is calculated on the basis of 82.30′ E longitude which divided India into two halves.
- It is taken as the standard time as it passes through almost the centre of India. But it is worth remembering that it operate a single Time Zone, not for Daylight Saving Time.
- But the country’s east–west distance is more than 2,933 kilometres (1,822 mi) covers over 29 degrees of longitude, resulting in the sun rising and setting almost two hours earlier on India’s eastern border than in the Rann of Kutch in the far west.
- The people of the north-eastern states have to advance their clocks with the early sunrise and avoid the extra consumption of energy after daylight hours.
- In the modern age, it will be nearly impossible to set ‘odd’ time zones.
- Proponents of a single time zone argue that India is not as wide as China, which continues to have a single time zone (the country actually spreads across five time zones).
- China’s adoption of a single time zone (Beijing Time GMT+8) was a result of a communist doctrine in 1949. It is now being questioned by party officials, finally. Also, the people of Xinjiang, China’s western-most Province, unofficially follow a time zone that is two hours behind Beijing time.
- But there is another aspect, common to the Chinese and Indian desires to maintain single time zones over vast nations — the ‘unity’ theory. A single time, a single shared experience, no matter where you are in India, unifies the nation.
- That is definitely a strong ideal, but also slightly flawed because it does not take advantage of the light.
- Changing time zones when we travel internationally can seriously disturb physical cycles.
- If the sun rises too early and sets too early, or vice versa, as per the local time, it can also disturb body cycles.
- There are also economic benefits to having two different time zones; people will be able to work better and plan better, according to natural cycles rather than the one imposed by the state.