Time database

Mailing list

• http://groups.yahoo.com/groups/tk-db

Desired features

Time keeping database (tkdb)	IANA time zone database (tzdb)
Exactly one term for one kind of object	Terms are used interchangeably (region = zone) Terms are used ambiguously (zone for IANA zones and real world zones)
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 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)
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.	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 Different locations are linked, e.g. Vaduz points to Zurich, Tel Aviv to Jerusalem
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	no time for Bouvet Island, while Norwegian government has defined it, limited support for pre-1970 data
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.