It wasn’t always so. The British, ever so particular about maximum output in their commercial ventures, had a "local time" set one hour ahead of the IST for operations in the tea gardens, coal mines and the oil industry of Assam. Reminisces Shantikam Hazarika, who’s worked in the oil industry and is currently director of the Assam Institute of Management: "In the oil sector, we used to apply ‘local time’ till 1973. It made sense since solar time at 5.30 am IST in Assam was like 6.30 am in Madras and about 7 am in Bombay. Moreover, because of this practice the administrative offices in the oil sector worked in tandem with the shift hours. Unfortunately, that practice was abolished for some reason."