rfc9581v2.txt | rfc9581.txt | |||
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skipping to change at line 143 ¶ | skipping to change at line 143 ¶ | |||
document beyond its direct use in Sections 3.6 and 3.7. | document beyond its direct use in Sections 3.6 and 3.7. | |||
2. Objectives | 2. Objectives | |||
For the time tag, the present specification addresses the following | For the time tag, the present specification addresses the following | |||
objectives that go beyond the original tags 0 and 1 (defined in | objectives that go beyond the original tags 0 and 1 (defined in | |||
Sections 3.4.1 and 3.4.2 of [RFC8949]): | Sections 3.4.1 and 3.4.2 of [RFC8949]): | |||
* Additional resolution for epoch-based time (as in tag 1). CBOR | * Additional resolution for epoch-based time (as in tag 1). CBOR | |||
tag 1 only provides for representation of time as an integer and | tag 1 only provides for representation of time as an integer and | |||
as up to a binary64 floating-point value, which limits the | as up to a binary64 floating-point value [IEEE754], which limits | |||
resolution to approximately microseconds at the time of writing | the resolution to approximately microseconds at the time of | |||
(and progressively becoming worse over time). | writing (and progressively becoming worse over time). | |||
* Indication of timescale. Tags 0 and 1 are defined for UTC; | * Indication of timescale. Tags 0 and 1 are defined for UTC; | |||
however, some interchanges are better performed on TAI. Other | however, some interchanges are better performed on TAI. Other | |||
timescales may be registered once they become relevant (e.g., one | timescales may be registered once they become relevant (e.g., one | |||
of the proposed successors to UTC that might no longer use leap | of the proposed successors to UTC that might no longer use leap | |||
seconds or a scale based on smeared leap seconds). | seconds or a scale based on smeared leap seconds). | |||
By incorporating a way to transport [RFC9557] suffix information (see | By incorporating a way to transport [RFC9557] suffix information (see | |||
Sections 3.6 and 3.7), additional indications of intents about the | Sections 3.6 and 3.7), additional indications of intents about the | |||
interpretation of the time given can be provided; in particular, for | interpretation of the time given can be provided; in particular, for | |||
skipping to change at line 635 ¶ | skipping to change at line 635 ¶ | |||
duration = #6.1002({* (int/tstr) => any}) | duration = #6.1002({* (int/tstr) => any}) | |||
period = #6.1003([~etime/null, ~etime/null, ~duration/null]) | period = #6.1003([~etime/null, ~etime/null, ~duration/null]) | |||
Figure 5: Recommended Type Names for CDDL | Figure 5: Recommended Type Names for CDDL | |||
7. IANA Considerations | 7. IANA Considerations | |||
7.1. CBOR Tags | 7.1. CBOR Tags | |||
In the "CBOR Tags" registry [IANA.cbor-tags], IANA has allocated the | In the "CBOR Tags" registry [IANA.cbor-tags], IANA has allocated the | |||
tags in Table 2 out of the First Come First Served (FCFS) range and | tags in Table 2. | |||
listed this document as the specification reference. | ||||
+======+===========+====================================+ | +======+===========+===============+======================+ | |||
| Tag | Data Item | Semantics | | | Tag | Data Item | Semantics | Reference | | |||
+======+===========+====================================+ | +======+===========+===============+======================+ | |||
| 1001 | map | [RFC9581, Section 3] extended time | | | 1001 | map | extended time | [RFC9581, Section 3] | | |||
+------+-----------+------------------------------------+ | +------+-----------+---------------+----------------------+ | |||
| 1002 | map | [RFC9581, Section 4] duration | | | 1002 | map | duration | [RFC9581, Section 4] | | |||
+------+-----------+------------------------------------+ | +------+-----------+---------------+----------------------+ | |||
| 1003 | array | [RFC9581, Section 5] period | | | 1003 | array | period | [RFC9581, Section 5] | | |||
+------+-----------+------------------------------------+ | +------+-----------+---------------+----------------------+ | |||
Table 2: Values for Tags | Table 2: Values for Tags | |||
IANA has updated the "Data Item" column for tag 1003 from "map" to | IANA has updated the "Data Item" column for tag 1003 from "map" to | |||
"array". | "array". | |||
7.2. Timescales Registry | 7.2. Timescales Registry | |||
Per this specification, IANA has created a new "Timescales" registry | Per this specification, IANA has created a new "Timescales" registry | |||
within the "Concise Binary Object Representation (CBOR) Tags" | within the "Concise Binary Object Representation (CBOR) Tags" | |||
skipping to change at line 854 ¶ | skipping to change at line 853 ¶ | |||
V1_chap04.html#tag_04_16>. | V1_chap04.html#tag_04_16>. | |||
9.2. Informative References | 9.2. Informative References | |||
[C] ISO, "Information technology -- Programming languages -- | [C] ISO, "Information technology -- Programming languages -- | |||
C", Fourth Edition, ISO/IEC 9899:2018, June 2018, | C", Fourth Edition, ISO/IEC 9899:2018, June 2018, | |||
<https://www.iso.org/standard/74528.html>. Contents | <https://www.iso.org/standard/74528.html>. Contents | |||
available via <https://www.open- | available via <https://www.open- | |||
std.org/jtc1/sc22/wg14/www/docs/n2310.pdf> | std.org/jtc1/sc22/wg14/www/docs/n2310.pdf> | |||
[IEEE754] IEEE, "IEEE Standard for Floating-Point Arithmetic", | ||||
IEEE 754-2019, DOI 10.1109/IEEESTD.2019.8766229, July | ||||
2019, <https://ieeexplore.ieee.org/document/8766229>. | ||||
[ISO8601-1:2019] | [ISO8601-1:2019] | |||
ISO, "Date and time -- Representations for information | ISO, "Date and time -- Representations for information | |||
interchange -- Part 1: Basic rules", ISO 8601-1:2019, | interchange -- Part 1: Basic rules", ISO 8601-1:2019, | |||
February 2019, <https://www.iso.org/standard/70907.html>. | February 2019, <https://www.iso.org/standard/70907.html>. | |||
[ISO8601:1988] | [ISO8601:1988] | |||
ISO, "Data elements and interchange formats -- Information | ISO, "Data elements and interchange formats -- Information | |||
interchange -- Representation of dates and times", | interchange -- Representation of dates and times", | |||
ISO 8601:1988, June 1988, | ISO 8601:1988, June 1988, | |||
<https://www.iso.org/standard/15903.html>. Also available | <https://www.iso.org/standard/15903.html>. Also available | |||
End of changes. 4 change blocks. | ||||
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