--- 1/draft-ietf-cbor-date-tag-04.txt 2020-07-17 08:13:14.880133127 -0700 +++ 2/draft-ietf-cbor-date-tag-05.txt 2020-07-17 08:13:14.896133534 -0700 @@ -1,88 +1,89 @@ CBOR Working Group M. Jones Internet-Draft A. Nadalin Intended status: Standards Track Microsoft -Expires: January 15, 2021 J. Richter +Expires: January 17, 2021 J. Richter pdv Financial Software GmbH - July 14, 2020 + July 16, 2020 Concise Binary Object Representation (CBOR) Tags for Date - draft-ietf-cbor-date-tag-04 + draft-ietf-cbor-date-tag-05 Abstract The Concise Binary Object Representation (CBOR, RFC 7049) is a data format whose design goals include the possibility of extremely small code size, fairly small message size, and extensibility without the need for version negotiation. In CBOR, one point of extensibility is the definition of CBOR tags. RFC 7049 defines two tags for time: CBOR tag 0 (RFC 3339 date/time string) and tag 1 (Posix "seconds since the epoch"). Since then, additional requirements have become known. This specification defines a CBOR tag for an RFC 3339 date text string, for applications needing a textual date representation within the Gregorian calendar without a time. It also defines a CBOR tag for days since the date 1970-01-01 in the Gregorian calendar for applications needing a - numeric date representation without a time. It is intended as the - reference document for the IANA registration of the CBOR tags - defined. + numeric date representation without a time. This specification is + intended as the reference document for IANA registration of the CBOR + tags defined. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on January 15, 2021. + This Internet-Draft will expire on January 17, 2021. Copyright Notice Copyright (c) 2020 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 (https://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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Calendar Dates . . . . . . . . . . . . . . . . . . . . . 3 - 1.2. Comparing Dates . . . . . . . . . . . . . . . . . . . . . 3 - 1.3. Comparing Dates and Times . . . . . . . . . . . . . . . . 3 + 1.1.1. Example Date Representations . . . . . . . . . . . . 3 + 1.2. Comparing Dates . . . . . . . . . . . . . . . . . . . . . 4 + 1.3. Comparing Dates and Date/Time Values . . . . . . . . . . 4 2. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 2.1. Concise Binary Object Representation (CBOR) Tags Registrations . . . . . . . . . . . . . . . . . . . . . . 4 - 3. Security Considerations . . . . . . . . . . . . . . . . . . . 4 - 4. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 4.1. Normative References . . . . . . . . . . . . . . . . . . 4 + 3. Security Considerations . . . . . . . . . . . . . . . . . . . 5 + 4. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 + 4.1. Normative References . . . . . . . . . . . . . . . . . . 5 4.2. Informative References . . . . . . . . . . . . . . . . . 5 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 5 - Document History . . . . . . . . . . . . . . . . . . . . . . . . 5 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 + Document History . . . . . . . . . . . . . . . . . . . . . . . . 6 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 1. Introduction The Concise Binary Object Representation (CBOR) [RFC7049] provides for the interchange of structured data without a requirement for a pre-agreed schema. RFC 7049 defines a basic set of data types, as well as a tagging mechanism that enables extending the set of data types supported via an IANA registry. This specification defines a CBOR tag for a text string representing @@ -100,72 +101,93 @@ Julian Date minus 40587. Note that since both tags are for dates without times, times of day, time zones, and leap seconds are not applicable to these values. These tags are both for representations of Gregorian calendar dates. 1.1. Calendar Dates Calendar dates are used for numerous human use cases, such as marking the dates of significant events. For instance, John Lennon was born - on October 9, 1940 and died on December 8, 1980. One such common use - case is driver's licenses, which typically include a date of birth. - The dates used in this specification use the Gregorian calendar, as - do those in RFC 3339 [RFC3339]. The time zones and actual times of + on October 9, 1940 and died on December 8, 1980. One such use case + is driver's licenses, which typically include a date of birth. The + dates used in this specification use the Gregorian calendar, as do + those in RFC 3339 [RFC3339]. The time zones and actual times of these events are intentionally not represented in the calendar date. The epoch chosen for the second tag, which represents days since the Gregorian calendar date 1970-01-01, is related to the IEEE Std 1003.1, 2013 Edition [POSIX.1] time epoch 1970-01-01T00:00:00Z UTC only insofar as both contain the date 1970-01-01. This should not be construed as indicating that dates using this tag represent either a specific time of day and/or time zone. The day of the week (Sunday, Monday, Tuesday, etc.) is not explicitly represented in either of these date formats. However, deterministic algorithms that are beyond the scope of this specification can be used to derive the day of the week in the Gregorian calendar from dates represented in both of these formats. +1.1.1. Example Date Representations + + This table contains example representations for dates using both + tags. + + +------------------+--------------+---------+ + | Date | Tag 1004 | Tag 100 | + +------------------+--------------+---------+ + | October 9, 1940 | "1940-10-09" | -10676 | + | December 8, 1980 | "1980-12-08" | 3994 | + +------------------+--------------+---------+ + 1.2. Comparing Dates Comparison of dates in "full-date" format can be accomplished by normal string comparison, since by design, the digits representing the date are in fixed format and ordered from most significant to least significant. Comparison of numeric dates representing days since 1970-01-01 can be performed by normal integer comparison. Comparison of dates in other formats or using other calendars require conversions that are beyond the scope of this specification. -1.3. Comparing Dates and Times + Note that different dates may correspond to the same moment in time, + depending upon the time zone in which the date was determined. For + instance, at many times of the day, a conference call occurring on a + particular date in Japan will simultaneously occur on the previous + date in Hawaii; at many times of the day, Japan's Friday corresponds + with Hawaii's Thursday. - Comparing dates with times is beyond the scope of this specification. - That said, if a date is augmented with a time zone and time of day, - comparing that augmented date with other times becomes possible. For - instance, if one were to augment John Lennon's birth date of October - 9, 1940 with the time of day and time zone of his birth, then it - would be possible to derive a time at which he was born that could be - compared with other times. +1.3. Comparing Dates and Date/Time Values + + Comparing dates with date/time values, which represent a particular + moment in time, is beyond the scope of this specification. That + said, if a date is augmented with a time zone and time of day, a + specific date/time value can be determined and comparing that date/ + time value to others becomes possible. For instance, if one were to + augment John Lennon's birth date of October 9, 1940 with the time of + day and time zone of his birth, then it would be possible to derive a + date/time at which he was born that could be compared with other + date/time values. 2. IANA Considerations 2.1. Concise Binary Object Representation (CBOR) Tags Registrations This section registers the following values in the IANA "Concise Binary Object Representation (CBOR) Tags" registry [IANA.cbor-tags]. - o Tag: 1004 (value requested) + o Tag: 1004 o Data Item: UTF-8 text string o Semantics: RFC 3339 full-date string o Reference: [[ this specification ]] - o Tag: 100 (ASCII 'd') (value requested) + o Tag: 100 (ASCII 'd') o Data Item: Unsigned or negative integer o Semantics: Number of days since the epoch date 1970-01-01 o Reference: [[ this specification ]] 3. Security Considerations The security considerations of RFC 7049 apply; the tags introduced here are not expected to raise security considerations beyond those. A date, of course, has significant security considerations. These @@ -210,20 +232,25 @@ Thanks to these people for reviews of the specification: Henk Birkholz, Carsten Bormann, Thiago Macieira, Francesca Palombini, Michael Richardson, Jim Schaad, Juergen Schoenwaelder, and Dale Worley. Document History [[ to be removed by the RFC Editor before publication as an RFC ]] + -05 + + o Incorporated additional suggestions by Carsten Bormann and Juergen + Schoenwaelder. + -04 o Addressed shepherd comments by Francesca Palombini. o Addressed additional review comments by Jim Schaad and Michael Richardson. -03 o Added statement that these tags are both for representations of