Calcutta Time was one of the two officialtime zones established inBritish India in 1884. It was established during theInternational Meridian Conference held atWashington, D.C. in theUnited States. It was decided thatIndia had two time zones: Calcutta (nowKolkata) would use the90th meridian east and Bombay (nowMumbai) the75th meridian east. It was determined as 5 hours, 53 minutes and 20 seconds ahead ofGreenwich Mean Time (UTC+5:53:20).
Calcutta Time was described as being 23 minutes and 20 second ahead ofIndian standard time and one hour, two minutes and 20 seconds ahead ofBombay Time.[1] It has also been described as 32 minutes and 6 seconds ahead ofMadras Time (UTC+5:21:14).[2]
Even whenIndian Standard Time (IST) was adopted on 1 January 1906, Calcutta Time remained in effect until 1948 when it was abandoned in favour of IST.[3]
In the latter part of the nineteenth century, Calcutta Time was the dominant time of the Indian part of the British empire with records of astronomical and geological events recorded in it.[4][5] Willian Strachey, an uncle ofLytton Strachey was said to have visited Calcutta once and then "kept his own watch set resolutely to Calcutta Time, organizing the remaining fifty-six years of his life accordingly".[6][7]James Clavell, in his novelKing Rat, refers to news broadcasts as occurring in "Calcutta Time".[8]
