New Delhi, July 20: Setting all Indian clocks six hours ahead of Greenwich Mean Time will bring more energy savings than having two time zones in the country, experts said today while cautioning that separate time zones may bring adverse consequences.

Bhartruhari Mahtab, a Biju Janata Dal MP from Cuttack, had asked the Centre in the Lok Sabha yesterday to consider a separate time zone for the northeastern states to save on electricity by taking advantage of daylight hours.

At some locations in the region, the sun rises before 4.15am during the peak of the summer while setting by 4.15pm during a stretch of the winter.

Mahtab's suggestion comes against the backdrop of more than three decades of debate, punctuated by intermittent research reports analysing the pros and cons of switching to separate time zones, one for the eastern and northeastern states and another for the rest of India.

A panel set up by the Union government's department of science and technology had examined a two-time-zones proposal in 2003 and ruled that the likely costs outweighed any gains from energy savings.

"Any decision on time zones can only be a political decision," said a senior government official who requested not to be named. "This is a very sensitive issue."

Two researchers at the National Institute of Advanced Studies in Bangalore had five years ago analysed India's energy consumption patterns and argued that setting Indian Standard Time six hours ahead of GMT would be a better option than having two time zones. Currently, Indian time is 5.30 hours ahead of GMT.

Dilip Ahuja and D.P. Sengupta, teachers at the Bangalore institute, had examined multiple options, including two time zones, different winter and summer times, and shifting Indian time to either plus-6 GMT or plus-6.30 GMT. They found that the two-time-zones option yielded the smallest benefits in energy savings.

"Our calculations suggested that the plus-6 GMT option would give us the largest potential energy savings and also reduce the inconvenience experienced by populations in our Northeast," Ahuja told The Telegraph.

Ahuja and Sengupta had argued that having two time zones might also increase the risk of train accidents at places with single-line tracks that need to be manually switched.

Their analysis, carried out for the Bureau of Energy Efficiency, was "subsequently discussed at length with ministries and states", Ajay Mathur, former head of the bureau and now director-general of The Energy and Resources Institute (TERI), told this newspaper via email.

"However, no agreement could be reached on whether a change in the current time structure is needed," Mathur wrote.

Government officials and researchers say there are fears about the possible adverse effects of switching to two time zones.

"They're not easy to articulate; they may seem far-fetched; but these concerns relate to the possible impacts of creating a new artificial division within the country," Sengupta told this newspaper.

A senior government official cited how China, despite its even larger east-west spread than India, has maintained a single time zone.

He said the government had suggested to the northeastern states over a decade ago that they take administrative steps such as tailoring the school and office timings to the daylight hours in the region.

The Andaman and Nicobar Islands have been following this practice of altered timings for more than 15 years now, a department of science and technology official said.

A team of TERI researchers had in the late 1980s conducted one of the first-ever systematic studies of the benefits of having two time zones. It had concluded that the option was not recommended even from the perspective of energy savings.