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3319. Properly reference specification of IANA time zone database

Section: 27.11.1 [] Status: C++20 Submitter: Germany Opened: 2019-11-05 Last modified: 2021-02-25

Priority: 0

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Addresses DE 344

This paragraph says

"27.11 describes an interface for accessing the IANA Time Zone database described in RFC 6557, …"

However, RFC 6557 does not describe the database itself; it only describes the maintenance procedures for that database, as its title implies (quoted in clause 2).

Proposed change:

Add a reference to a specification of the database itself, or excise all references to the IANA time zone database.

Howard Hinnant:

We can not entirely remove the reference to IANA because we need portable time_zone names (e.g. "America/New_York") and definitions. However the NB comment is quite accurate and fixed with the proposed resolution.

[2019-11 Status to Ready during Wednesday morning issue processing in Belfast.]

Proposed resolution:

This wording is relative to N4835.

  1. Modify 2 [intro.refs] as indicated:

    -1- The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

    1. […]

    2. (1.2) — INTERNET ENGINEERING TASK FORCE (IETF). RFC 6557: Procedures for Maintaining the Time Zone Database [online]. Edited by E. Lear, P. Eggert. February 2012 [viewed 2018-03-26]. Available at

    3. […]

  2. Modify 27.11.1 [] as indicated:

    -1- 27.11 [] describes an interface for accessing the IANA Time Zone dDatabase described in RFC 6557, that interoperates with sys_time and local_time. This interface provides time zone support to both the civil calendar types (27.8 []) and to user-defined calendars.

  3. Modify section "Bibliography" as indicated:

    The following documents are cited informatively in this document.

    1. — IANA Time Zone Database. Available at

    2. — ISO/IEC 10967-1:2012, Information technology — Language independent arithmetic — Part 1: Integer and floating point arithmetic

    3. […]