Time Zone Data Distribution Service
RFC 7808
Internet Engineering Task Force (IETF) M. Douglass
Request for Comments: 7808 Spherical Cow Group
Category: Standards Track C. Daboo
ISSN: 2070-1721 Apple
March 2016
Time Zone Data Distribution Service
Abstract
This document defines a time zone data distribution service that
allows reliable, secure, and fast delivery of time zone data and
leap-second rules to client systems such as calendaring and
scheduling applications or operating systems.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7808.
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Douglass & Daboo Standards Track [Page 1]
RFC 7808 TZDIST Service March 2016
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Conventions . . . . . . . . . . . . . . . . . . . . . . . 4
2. Architectural Overview . . . . . . . . . . . . . . . . . . . 5
3. General Considerations . . . . . . . . . . . . . . . . . . . 7
3.1. Time Zone . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2. Time Zone Data . . . . . . . . . . . . . . . . . . . . . 7
3.3. Time Zone Metadata . . . . . . . . . . . . . . . . . . . 7
3.4. Time Zone Data Server . . . . . . . . . . . . . . . . . . 7
3.5. Observance . . . . . . . . . . . . . . . . . . . . . . . 7
3.6. Time Zone Identifiers . . . . . . . . . . . . . . . . . . 7
3.7. Time Zone Aliases . . . . . . . . . . . . . . . . . . . . 8
3.8. Time Zone Localized Names . . . . . . . . . . . . . . . . 8
3.9. Truncating Time Zones . . . . . . . . . . . . . . . . . . 9
3.10. Time Zone Versions . . . . . . . . . . . . . . . . . . . 10
4. Time Zone Data Distribution Service Protocol . . . . . . . . 10
4.1. Server Protocol . . . . . . . . . . . . . . . . . . . . . 10
4.1.1. Time Zone Queries . . . . . . . . . . . . . . . . . . 11
4.1.2. Time Zone Formats . . . . . . . . . . . . . . . . . . 11
4.1.3. Time Zone Localization . . . . . . . . . . . . . . . 12
4.1.4. Conditional Time Zone Requests . . . . . . . . . . . 12
4.1.5. Expanded Time Zone Data . . . . . . . . . . . . . . . 14
4.1.6. Server Requirements . . . . . . . . . . . . . . . . . 14
4.1.7. Error Responses . . . . . . . . . . . . . . . . . . . 14
4.1.8. Extensions . . . . . . . . . . . . . . . . . . . . . 14
4.2. Client Guidelines . . . . . . . . . . . . . . . . . . . . 14
4.2.1. Discovery . . . . . . . . . . . . . . . . . . . . . . 14
4.2.1.1. SRV Service Labels for the Time Zone Data
Distribution Service . . . . . . . . . . . . . . 15
4.2.1.2. TXT Records for a Time Zone Data Distribution
Service . . . . . . . . . . . . . . . . . . . . . 15
4.2.1.3. Well-Known URI for a Time Zone Data Distribution
Service . . . . . . . . . . . . . . . . . . . . . 16
4.2.1.3.1. Example: Well-Known URI Redirects to Actual
Context Path . . . . . . . . . . . . . . . . 17
4.2.2. Synchronization of Time Zones . . . . . . . . . . . . 17
4.2.2.1. Initial Synchronization of All Time Zones . . . . 17
4.2.2.2. Subsequent Synchronization of All Time Zones . . 17
4.2.2.3. Synchronization with Preexisting Time Zone Data . 18
5. Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.1. "capabilities" Action . . . . . . . . . . . . . . . . . . 18
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