[tz] Suggesting an ISO standard for time zone identification - possible replacement of IANA abbreviations

Tobias Conradi mail.2012 at tobiasconradi.com
Tue Apr 16 12:50:00 UTC 2013

Dear Mr. Carpenter,

this email is send to you, because you are listed as the secretary for
the "TC 46/SC 9 Identification and description". Maybe you can forward
it to the relevant office or tell me where else I can email to.

I suggest that the ISO creates an ISO standard for time zone
identification. Current abbreviations in the IANA time zone database
are ambiguous, e.g. IST may refer to Israel Standard Time or India
Standard Time.

The standard could be used in the IANA time zone database and projects
that collect time zone related data, e.g. laws and translations of

Since time zone law is country related one could look whether ISO 3166
can be used.

The IANA time zone database has the stated aim of being correct for
all regions in the world after the year 1970. Although the earliest
ISO 3166 country code standard on the ISO website is ISO 3166:1981,
web search for ISO 3166 1974 gives several hits claiming the first
publication was in 1974. If there have been countries between 1970 and
1974 that have no ISO 3166 code one can use codes from the
user-assigned code space.

So the first two letters might be ISO 3166-1 alpha-2 country code
based. But I suggest checking whether the alpha-3 codes or numeric
codes are a better fit.

Further letters may then mark regions inside a country and special
restricted time shifts, e.g. daylight saving time.

Such a structured set could look like:
AUEDT - Australia Eastern Daylight saving Time
AUCDT - United States Central Daylight saving Time
AUWDT - Australia Western Daylight saving Time

EUEDT - EU Eastern Daylight saving Time
EUCDT - EU Central Daylight saving Time
EUWDT - EU Western Daylight saving Time

IDEST - Indonesia Eastern Standard Time
IDCST - Indonesia Central Standard Time
IDWST - Indonesia Western Standard Time

USEDT - United States Eastern Daylight saving Time
USCDT - United States Central Daylight saving Time
USPDT - United States Pacific Daylight saving Time

Kind regards
Tobias Conradi

Tobias Conradi
Rheinsberger Str. 18
10115 Berlin


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