City history
From medieval hamlets on the Hooghly to imperial capital and modern metropolis, Kolkata evolved from distinct local timekeeping to standard Indian Standard Time.
Chapter one
Earliest documented name
"Disputed; likely derived from Kalikshetra (field of Kali) or khal-kata (cut canal)"
First recorded in 15th-century Bengali literature and 16th-century Mughal revenue records, Kalikata was one of three riverside hamlets that formed the nucleus of modern Kolkata.
Disputed; associated with Goddess Kali's sacred territory or canal cuts along the river.
A riverside village on the east bank of the Hooghly River alongside Sutanuti and Gobindapur.
Anglicized form of Kalikata.
Adopted under English East India Company rule; served as capital of British India until 1911.
Colloquial Bengali pronunciation of Kalikata.
Officially adopted by the West Bengal state legislature in 2001 to reflect native Bengali usage.
Chapter two
Calcutta Time was formally established at UTC+5:53:20 based on the local meridian of the Kolkata observatory following the International Meridian Conference.
British India introduced Indian Standard Time (UTC+5:30), but Kolkata maintained Calcutta Time for local city and administrative matters.
India temporarily advanced standard clocks by one hour as a wartime daylight saving measure from May 1942 to October 1945.
Kolkata relinquished Calcutta Time and fully synchronized with Indian Standard Time (UTC+5:30) following Indian independence.
Chapter three
Job Charnock selected the location for an East India Company trading center, uniting Kalikata, Sutanuti, and Gobindapur.
The British East India Company established the observatory to determine precise local meridian time for navigation and surveying.
A high-precision clock built by royal clockmaker Benjamin Lewis Vulliamy of London was installed upon the cathedral's completion.
Manufactured by Gents of London, the massive two-dial Boro Ghori clock was mounted in Howrah Station, becoming Kolkata's primary public time landmark.
The city officially changed its name from Calcutta to Kolkata to match native Bengali orthography and pronunciation.