Madras Time
E32695
Madras Time was a former local time standard used in the Madras (now Chennai) region of India before the adoption of a unified national time zone.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Madras Time canonical | 3 |
How this entity was disambiguated
This entity first appeared as the object of triple T247374 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Madras Time Context triple: [Indian Standard Time, previousTimeSystemsIncluded, Madras Time]
-
A.
Calcutta Time
Calcutta Time was a former local time standard used in Kolkata (then Calcutta) before the adoption of a unified national time zone in India.
-
B.
Bombay Time
Bombay Time was a former local time standard used in the city of Bombay (now Mumbai) before the adoption of a unified national time across India.
-
C.
Indian Standard Time
Indian Standard Time is the time zone used throughout India, set at UTC+5:30.
-
D.
Moscow Time
Moscow Time is the standard time zone used in Moscow and much of western Russia, corresponding to UTC+3 year-round.
-
E.
Madras Port
Madras Port, now known as Chennai Port, is one of India’s oldest and busiest seaports, serving as a key maritime gateway on the southeastern coast of the country.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Madras Time Target entity description: Madras Time was a former local time standard used in the Madras (now Chennai) region of India before the adoption of a unified national time zone.
-
A.
Calcutta Time
Calcutta Time was a former local time standard used in Kolkata (then Calcutta) before the adoption of a unified national time zone in India.
-
B.
Bombay Time
Bombay Time was a former local time standard used in the city of Bombay (now Mumbai) before the adoption of a unified national time across India.
-
C.
Indian Standard Time
Indian Standard Time is the time zone used throughout India, set at UTC+5:30.
-
D.
Moscow Time
Moscow Time is the standard time zone used in Moscow and much of western Russia, corresponding to UTC+3 year-round.
-
E.
Madras Port
Madras Port, now known as Chennai Port, is one of India’s oldest and busiest seaports, serving as a key maritime gateway on the southeastern coast of the country.
- F. None of above. chosen
Statements (45)
| Predicate | Object |
|---|---|
| instanceOf |
local mean time
ⓘ
time standard ⓘ |
| basedOn | local mean solar time at Madras Observatory ⓘ |
| category |
Former time zones
ⓘ
History of Chennai ⓘ Time in India ⓘ Time zones of Asia ⓘ |
| country | British India ⓘ |
| countryAfterReplacement | Dominion of India ⓘ |
| geographicalScope |
Madras region
ⓘ
parts of southern India ⓘ |
| historicalPeriod |
19th century
ⓘ
early 20th century ⓘ |
| locatedIn |
Chennai
ⓘ
India ⓘ Madras ⓘ
linked to:
Chennai
Madras Observatory ⓘ Tamil Nadu ⓘ |
| longitudeReference | 80°18′30″E ⓘ |
| measurementBasis | mean solar time ⓘ |
| observatory | Madras Observatory ⓘ |
| offsetFromBombayTime | +00:39 ⓘ |
| offsetFromCalcuttaTime | −00:09 ⓘ |
| offsetFromGMT | +05:21 ⓘ |
| reasonForReplacement | adoption of a unified national time zone ⓘ |
| regionType | regional time standard ⓘ |
| relatedTo |
Bombay Time
ⓘ
Calcutta Time ⓘ Indian Standard Time ⓘ |
| replacedBy | Indian Standard Time ⓘ |
| standardizedBy | British colonial administration ⓘ |
| status | defunct ⓘ |
| timeZoneOf |
Chennai
ⓘ
Madras ⓘ
linked to:
Chennai
|
| usedBefore | adoption of Indian Standard Time in southern India ⓘ |
| usedBy |
Madras Presidency government
ⓘ
linked to:
Madras Presidency
railways in southern India ⓘ |
| usedFor |
administrative purposes in Madras Presidency
ⓘ
civil time in Madras region ⓘ railway timetables in Madras Presidency ⓘ |
| usedIn |
Chennai
ⓘ
Madras ⓘ
linked to:
Chennai
Madras Presidency ⓘ |
| utcOffset | +05:21 ⓘ |
| utcOffsetDescription | 5 hours 21 minutes ahead of UTC ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Madras Time Description of subject: Madras Time was a former local time standard used in the Madras (now Chennai) region of India before the adoption of a unified national time zone.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.