Assam Chief Minister Tarun Gogoi is campaigning to scrap India's single time zone, which causes problems for easterners who face summer sunrise as early as 4:30am.Despite India's vast size, it has one time of +5:30 from Greenwich Mean Time for its 1.2-billion population, spread from points further east than Bangladesh to the western Arabian Sea.At this time of year the sun rises in the east shortly before 6am, more than 90 minutes earlier than in the west, while daybreak in the east comes as early as 4:30am around the summer solstice."We need a local time for Assam and the other northeastern states which will be ahead of the Indian Standard Time (IST) by at least an hour to 90 minutes," said Mr Gogoi. "We have an early daybreak in the northeast compared to other parts of India and if we have a separate time zone then it would undoubtedly be very productive for all of us and would also help in saving energy," he added.He plans to lobby in New Delhi for a change, renewing a campaign which last gathered momentum in 2010.Mr Gogoi says sticking to Indian Standard Time means a loss of daylight hours and an attendant decrease in productivity for his state. For instance, a farmer in Assam can start work one hour before her or his counterpart in a state like GujaratHe points out that tea gardens in Assam have for years set their clocks an hour ahead of the rest of the country.The proposal for a different time zone will have to be cleared by the Centre.