Time database: Difference between revisions
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| Exactly one term for one kind of object | | Exactly one term for one kind of object | ||
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* Terms are used interchangeably (region = zone) | |||
* Terms are used ambiguously (zone for IANA zones and real world zones) | |||
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| | | Smallest geographic unit is named "sector" | ||
| Smallest geographic unit is named "zone" | | Smallest geographic unit is named "zone" | ||
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| Some areas are not covered, e.g. the ISO 3166 country "Bouvet Island" | | Some areas are not covered, e.g. the ISO 3166 country "Bouvet Island" | ||
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| New sectors are created only by splitting and deprecating old sectors, so a user can know if an ID needs a check for correctness. | | Each sector has exactly one sector ID. | ||
| Some zones have multiple IDs via links. These links can | |||
* represent former IDs of the zone due to spelling change for the reference location | |||
* represent former IDs of the zone due to reference location change (Tel Aviv -> Jerusalem) | |||
* represent IDs of former zones (Vaduz links to Zurich) | |||
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| New sectors are created only by splitting and deprecating old sectors, so a user can know if an assignment of an ID to an object needs a check for correctness. | |||
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* User can link an object to a tzid, but get's no notification if later the object is located in another zone having a different tzid | * User can link an object to a tzid, but get's no notification if later the object is located in another zone having a different tzid |
Revision as of 2013-09-20T20:19:55
Desired features:
Time keeping database (tkdb) | IANA time zone database (tzdb) |
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Exactly one term for one kind of object |
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Smallest geographic unit is named "sector" | Smallest geographic unit is named "zone" |
The sectors cover the whole surface of the earth | Some areas are not covered, e.g. the ISO 3166 country "Bouvet Island" |
Each sector has exactly one sector ID. | Some zones have multiple IDs via links. These links can
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New sectors are created only by splitting and deprecating old sectors, so a user can know if an assignment of an ID to an object needs a check for correctness. |
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Relations between deprecated sectors and the sectors that have been created out of them are published. | No split history is explicitly published. |
Record all legal time |
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Provide time zone acronyms that are unique within each country and at any given point in time refer to only one offset from a base time | Uses EST and CST for time stamps of zones in Australia that use DST and those that do not. That means for a given point in time during summer the offset from UTC and therefore UTC itself cannot be derived from the local time representation. |
ISO 3166-1 alpha-3 codes for countries | ISO 3166-1 alpha-2 codes for countries. Some of the codes have been re-assigned, e.g. CS can refer to Czechoslovakia or Serbia and Montenegro. |