Madras Time was a time zone established in 1802 by John Goldingham, the first official astronomer of the British East India Company in India when he determined the longitude of Madras as 5 hours, 21 minutes and 14 seconds ahead of Greenwich Mean Time. It has been described as 9 minutes from UTC+5:30 and 33 minutes and 20 seconds behind Calcutta time which puts it at (UTC+5:21). Before India's independence, it was the closest precursor to Indian Standard Time which is derived from the location of the observatory at 82.5°E longitude in Shankargarh Allahabad in Uttar Pradesh.
After Bombay time and Calcutta time were set up as the two official time zones of British India in 1884, railway companies in India began to use Madras time as an intermediate time zone between the two zones. This led to Madras time also being known as "Railway time of India".
- William Nicholson, ed. (1809). "Eclipses of the Satellites of Jupiter, observed by John Goldingham and under his Superintendence, at Madras, in the East Indies". A Journal of Natural Philosophy, Chemistry, and the Arts (London: Stratford, Crown Court and Temple Bar) 22: 153–156.
- "On Time in India". Proceedings of the Asiatic Society of Bengal (Calcutta: Asiatic Society of Bengal): 49–55. April 1899.
- "On the Introduction of a Standard Time for India". Proceedings of the Asiatic Society of Bengal (Calcutta: Asiatic Society of Bengal): 62–66. June 1899.
- "Odds and Ends". Indian Railways Fan Club. Retrieved 2013-06-03.