Time in India
Encyclopedia
Time in India
since after independence in 1947
is officially represented by the Indian Standard Time
(IST, UTC+05:30). Some older time zones were:
The official time signal is given by the Time and Frequency Standards Laboratory
. The tz zone identifier for all India nowadays is Asia/Kolkata
.
During the Sino–Indian War of 1962 and the Indo–Pakistani Wars of 1965 and 1971, daylight saving was briefly used to reduce civilian energy consumption. The date and time notation in India shows some specialties.
treatise Surya Siddhanta
. Postulating a spherical earth
, the book defined the prime meridian
, or zero longitude, as passing through Avanti
, the ancient name for the historic city of Ujjain
(23°10′58"N 75°46′38"E), and Rohitaka, the ancient name for Rohtak
(28°54′N 76°38′E), a city near the Kurukshetra
.
The day used by ancient Indian astronomers began at sunrise at the prime meridian of Ujjain, and was divided into smaller time units in the following manner:
Taking a day to be 24 hours, the smallest time unit, prāṇa, or one respiratory cycle, equals 4 seconds, a value consistent with the normal breathing frequency of 15 breaths/min used in modern medical research. The Surya Siddhanta also described a method of converting local time to the standard time of Ujjain. Despite these early advances, standard time was not widely used outside astronomy. For most of India's history
, ruling kingdoms kept their own local time, typically using the Hindu calendar
in both lunar
and solar
units. For example, the Jantar Mantar
observatory built by Maharaja Sawai Jai Singh
in Jaipur
in 1733 contains large sundial
s, up to 90 ft (27 m) high, which were used to accurately determine the local time.
was set up by John Goldingham
and this was used widely by the railways in India. Though British India
did not officially adopt the standard time zones until 1905, when the meridian passing east of Allahabad at 82.5° E longitude was picked as the central meridian for India, corresponding to a single time zone for the country. This came into force on 1 January 1906, and also applied to Sri Lanka
(then Ceylon). However, Calcutta time was officially maintained as a separate time zone until 1948.
In 1925, time synchronisation began to be relayed through omnibus telephone systems and control circuits to organisations that needed to know the precise time. This continued until the 1940s, when time signals began to be broadcast using the radio by the government. Briefly during World War II, clocks under Indian Standard Time were advanced by one hour, calling it as War Time. This provision lasted from September 1, 1942 to October 14, 1945.
, the Indian government
established IST as the official time for the whole country, although Bombay and Calcutta retained their own local time for a few more years.
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
since after independence in 1947
Indian independence movement
The term Indian independence movement encompasses a wide area of political organisations, philosophies, and movements which had the common aim of ending first British East India Company rule, and then British imperial authority, in parts of South Asia...
is officially represented by the Indian Standard Time
Indian Standard Time
Indian Standard Time is the time observed throughout India and Sri Lanka, with a time offset of UTC+05:30. India does not observe daylight saving time or other seasonal adjustments, although DST was used briefly during the Sino–Indian War of 1962 and the Indo–Pakistani Wars of 1965 and 1971...
(IST, UTC+05:30). Some older time zones were:
- Bombay time (UTC+04:51),
- Calcutta timeCalcutta timeCalcutta time was one of the two time zones established in British India in 1884. It was established during the International Meridian Conference held at Washington, D.C in the United States. It was then decided that India were to have two time zones, with Calcutta would use the 90th meridian east...
(UTC+05:30:21), - Madras timeMadras timeMadras Time was a time zone set up in 1802 by John Goldingham, the first official astronomer of the British East India Company in India. It was set to 5 hours and 30 minutes ahead of Greenwich Mean Time...
(UTC+05:30) - Port Blair mean timePort Blair mean timePort Blair mean time was the time zone of the Andaman and Nicobar Islands of India in the Bay of Bengal. The time zone was set up during the early 19th century remained in effect until January 1, 1906 as the Indian Standard Time became the official time of India.-See also:* Indian Standard Time*...
.
The official time signal is given by the Time and Frequency Standards Laboratory
Time and Frequency Standards Laboratory
The Time and Frequency Standards Laboratory is a part of the National Physical Laboratory in New Delhi which maintains and calibrates the Indian Standard Time.Features of the Time and Frequency Standards Lab include:* Four caesium and rubidium atomic clocks...
. The tz zone identifier for all India nowadays is Asia/Kolkata
Asia/Kolkata
Asia/Kolkata is a time zone identifier from the zone file of the tz database. The data is as follows: The reference point is Kolkata....
.
During the Sino–Indian War of 1962 and the Indo–Pakistani Wars of 1965 and 1971, daylight saving was briefly used to reduce civilian energy consumption. The date and time notation in India shows some specialties.
Ancient India
One of the earliest known descriptions of standard time in India appeared in the 4th century CE astronomicalHindu astronomy
Historical Indian astronomy develops as a discipline of Vedanga or one of the "auxiliary disciplines" associated with the study of the Vedas.The oldest extant text of astronomy is the treatise by Lagadha, dated to the Mauryan era ....
treatise Surya Siddhanta
Surya Siddhanta
The Surya Siddhanta is one of the earliest siddhanta in archeo-astronomy of the Hindus by an unknown author. It describes the archeo-astronomy theories, principles and methods of the ancient Hindus. This siddhanta is supposed to be the knowledge that the Sun god gave to an Asura called Maya. Asuras...
. Postulating a spherical earth
Spherical Earth
The concept of a spherical Earth dates back to ancient Greek philosophy from around the 6th century BC, but remained a matter of philosophical speculation until the 3rd century BC when Hellenistic astronomy established the spherical shape of the earth as a physical given...
, the book defined the prime meridian
Prime Meridian
The Prime Meridian is the meridian at which the longitude is defined to be 0°.The Prime Meridian and its opposite the 180th meridian , which the International Date Line generally follows, form a great circle that divides the Earth into the Eastern and Western Hemispheres.An international...
, or zero longitude, as passing through Avanti
Avanti (India)
Avanti was an ancient Indian janapada , roughly corresponded to the present day Malwa region. According to the Buddhist text, the Anguttara Nikaya, Avanti was one of the solasa mahajanapadas of the 6th century BCE...
, the ancient name for the historic city of Ujjain
Ujjain
Ujjain , is an ancient city of Malwa region in central India, on the eastern bank of the Kshipra River , today part of the state of Madhya Pradesh. It is the administrative centre of Ujjain District and Ujjain Division.In ancient times the city was called Ujjayini...
(23°10′58"N 75°46′38"E), and Rohitaka, the ancient name for Rohtak
Rohtak
Rohtak City is a Municipal Corporation in Rohtak district that styles itself as the "Heart of Haryana". It is located 70 km Northwest of New Delhi and 210 km South of the state capital Chandigarh at the NH 10...
(28°54′N 76°38′E), a city near the Kurukshetra
Kurukshetra
Kurukshetra is a land of historical and religious importance. Historically the land belonged to Punjab now a district in Haryana state of India. It is a holy place and is also known as Dharmakshetra . According to the Puranas, Kurukshetra is named after King Kuru, the ancestor of Kauravas and...
.
The day used by ancient Indian astronomers began at sunrise at the prime meridian of Ujjain, and was divided into smaller time units in the following manner:
Time that is measurable is that which is in common use, beginning with the prāṇa (or, the time span of one breath). The pala contains six . The ghalikā is 60 palas, and the , or astronomical day, contains 60 ghalikās. A , or astronomical month, consists of 30 days.
Taking a day to be 24 hours, the smallest time unit, prāṇa, or one respiratory cycle, equals 4 seconds, a value consistent with the normal breathing frequency of 15 breaths/min used in modern medical research. The Surya Siddhanta also described a method of converting local time to the standard time of Ujjain. Despite these early advances, standard time was not widely used outside astronomy. For most of India's history
History of India
The history of India begins with evidence of human activity of Homo sapiens as long as 75,000 years ago, or with earlier hominids including Homo erectus from about 500,000 years ago. The Indus Valley Civilization, which spread and flourished in the northwestern part of the Indian subcontinent from...
, ruling kingdoms kept their own local time, typically using the Hindu calendar
Hindu calendar
The hindu calendar used in ancient times has undergone many changes in the process of regionalization, and today there are several regional Indian calendars, as well as an Indian national calendar. Nepali calendar, Bengali calendar, Malayalam calendar, Tamil calendar, Telugu calendar, Kannada...
in both lunar
Sidereal time
Sidereal time is a time-keeping system astronomers use to keep track of the direction to point their telescopes to view a given star in the night sky...
and solar
Solar time
Solar time is a reckoning of the passage of time based on the Sun's position in the sky. The fundamental unit of solar time is the day. Two types of solar time are apparent solar time and mean solar time .-Introduction:...
units. For example, the Jantar Mantar
Jantar Mantar (Jaipur)
The Jantar Mantar is a collection of architectural astronomical instruments, built by Maharaja Jai Singh II at his then new capital of Jaipur between 1727 and 1734. It is modeled after the one that he had built for him at the Mughal capital of Delhi. He had constructed a total of five such...
observatory built by Maharaja Sawai Jai Singh
Jai Singh II of Amber
Maharaja Sawai Jai Singh was ruler of the kingdom of Amber . He was born at Amber, the capital of the Kachwahas. He became ruler of Amber at the age of 11 after his father Maharaja Bishan Singh died on 31 December 1699...
in Jaipur
Jaipur
Jaipur , also popularly known as the Pink City, is the capital and largest city of the Indian state of Rajasthan. Founded on 18 November 1727 by Maharaja Sawai Jai Singh II, the ruler of Amber, the city today has a population of more than 3.1 million....
in 1733 contains large sundial
Sundial
A sundial is a device that measures time by the position of the Sun. In common designs such as the horizontal sundial, the sun casts a shadow from its style onto a surface marked with lines indicating the hours of the day. The style is the time-telling edge of the gnomon, often a thin rod or a...
s, up to 90 ft (27 m) high, which were used to accurately determine the local time.
Time under British rule in India
In 1802 Madras timeMadras time
Madras Time was a time zone set up in 1802 by John Goldingham, the first official astronomer of the British East India Company in India. It was set to 5 hours and 30 minutes ahead of Greenwich Mean Time...
was set up by John Goldingham
John Goldingham
John Goldingham was the first official astronomer of the Madras Observatory, appointed in 1802. Goldingham headed the Madras Survey School later which grew into the Guindy Engineering College and then Anna University...
and this was used widely by the railways in India. Though British India
British Raj
British Raj was the British rule in the Indian subcontinent between 1858 and 1947; The term can also refer to the period of dominion...
did not officially adopt the standard time zones until 1905, when the meridian passing east of Allahabad at 82.5° E longitude was picked as the central meridian for India, corresponding to a single time zone for the country. This came into force on 1 January 1906, and also applied to Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...
(then Ceylon). However, Calcutta time was officially maintained as a separate time zone until 1948.
In 1925, time synchronisation began to be relayed through omnibus telephone systems and control circuits to organisations that needed to know the precise time. This continued until the 1940s, when time signals began to be broadcast using the radio by the government. Briefly during World War II, clocks under Indian Standard Time were advanced by one hour, calling it as War Time. This provision lasted from September 1, 1942 to October 14, 1945.
After Independence
After independence in 1947Indian independence movement
The term Indian independence movement encompasses a wide area of political organisations, philosophies, and movements which had the common aim of ending first British East India Company rule, and then British imperial authority, in parts of South Asia...
, the Indian government
Government of India
The Government of India, officially known as the Union Government, and also known as the Central Government, was established by the Constitution of India, and is the governing authority of the union of 28 states and seven union territories, collectively called the Republic of India...
established IST as the official time for the whole country, although Bombay and Calcutta retained their own local time for a few more years.