However, when policies were made for independent India, the government decided to go with a single time zone, at longitude 82.5º east and 5.5 hours ahead of Greenwich Mean Time.Īll institutions across the country follow a single Indian Standard Time, even though sunrise and sunset times vary widely.

This qualifies for a twin time-zones setup.īefore Independence, India had two time zones – Bombay Time and Calcutta Time – in large part to help traders make use of daylight. Geographically, there is a 30-degree longitudinal difference between Arunachal Pradesh in the east and Gujarat in the west of India. Some 70 countries use neither daylight saving time nor multiple time zones, and India is among them. Some countries such as the US and France have multiple time zones and daylight saving time. As many as 70 countries in Africa and North and South America use daylight saving time – by setting their clocks forward, usually by an hour, from the standard in summer and back in winter – to make better use of daylight. Many countries such as Australia, the United Kingdom, France, Russia, New Zealand, Mexico and Brazil use multiple time zones across their territories. How time zones workĪs per convention, each time zone is spaced by 15 degrees’ longitude, which divides countries around the globe into 24 time zones to enable coordination – for railway and flight services, for example. “Back-of-the-envelope estimates suggest that India incurs annual human capital costs of roughly $4.1 billion (nearly Rs 29,000 crore) or 0.2% of nominal GDP due to the existing policy regulating time zone boundaries,” Maulik Jagnani, the author of the study, told IndiaSpend in an email interview.

Later sunset means people stay awake longer, which induces sleep deprivation among children and negatively affects their study efforts, a new study by a research scholar at Cornell University has found.Īs a result of sleeping late, children are less likely to complete primary and middle school, and this eﬀect is most pronounced among poor households, says the study, “Poor Sleep: Sunset Time and Human Capital Production”, which analysed the consequences India faces by operating under a single time zone. Each evening, the sun sets more than 90 minutes later in western India than in the east of the country, yet the entire country follows the same time zone.

India time zone gmt