<?xml version='1.0' encoding='utf-8'?>
<?xml-stylesheet type="text/xsl" href="rfc2629.xslt" ?>
<!-- generated by https://github.com/cabo/kramdown-rfc2629 version 1.4.12 -->
<!DOCTYPE rfc SYSTEM "rfc2629-xhtml.ent">
<?rfc toc="yes"?>
<?rfc sortrefs="yes"?>
<?rfc symrefs="yes"?>
<?rfc compact="yes"?>
<?rfc comments="yes"?>
<rfc xmlns:xi="http://www.w3.org/2001/XInclude" ipr="trust200902" docName="draft-ietf-cbor-time-tag-00" category="info" obsoletes="" updates="" submissionType="IETF" xml:lang="en" tocInclude="true" sortRefs="true" symRefs="true" version="3">
  <!-- xml2rfc v2v3 conversion 3.7.0 -->
  <front>
    <title abbrev="CBOR tag for extended time">Concise Binary Object Representation (CBOR) Tags for Time, Duration, and Period</title>
    <seriesInfo name="Internet-Draft" value="draft-ietf-cbor-time-tag-00"/>
    <author initials="C." surname="Bormann" fullname="Carsten Bormann">
      <organization>Universität Bremen TZI</organization>
      <address>
        <postal>
          <street>Postfach 330440</street>
          <city>Bremen</city>
          <code>D-28359</code>
          <country>Germany</country>
        </postal>
        <phone>+49-421-218-63921</phone>
        <email>cabo@tzi.org</email>
      </address>
    </author>
    <author initials="B." surname="Gamari" fullname="Ben Gamari">
      <organization>Well-Typed</organization>
      <address>
        <postal>
          <street>117 Middle Rd.</street>
          <city>Portsmouth</city>
          <region>NH</region>
          <code>03801</code>
          <country>United States</country>
        </postal>
        <email>ben@well-typed.com</email>
      </address>
    </author>
    <author initials="H." surname="Birkholz" fullname="Henk Birkholz">
      <organization abbrev="Fraunhofer SIT">Fraunhofer Institute for Secure Information Technology</organization>
      <address>
        <postal>
          <street>Rheinstrasse 75</street>
          <city>Darmstadt</city>
          <code>64295</code>
          <country>Germany</country>
        </postal>
        <email>henk.birkholz@sit.fraunhofer.de</email>
      </address>
    </author>
    <date year="2021" month="May" day="19"/>
    <keyword>Internet-Draft</keyword>
    <abstract>
      <t>The Concise Binary Object Representation (CBOR, RFC 8949) 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.</t>
      <t>In CBOR, one point of extensibility is the definition of CBOR tags.
RFC 8949 defines two tags for time: CBOR tag 0 (RFC3339 time as a string) and tag
1 (Posix time as int or float).  Since then, additional requirements have
become known.  The present document defines a CBOR tag for time that
allows a more elaborate representation of time, as well as related
CBOR tags for duration and time period.  It is
intended as the reference document for the IANA registration of the
CBOR tags defined.</t>
    </abstract>
    <note>
      <name>Note to Readers</name>
      <t>Version -00 of the individual submission that led to the present draft
opened up the possibilities provided by extended representations of
time in CBOR.
Version -01 consolidated this draft to non-speculative
content, the normative parts of which were believed will stay unchanged
during further development of the draft.  This version was provided to
aid the registration of the CBOR tag immediately needed.
Further versions of the individual submission made use of the IANA
allocations registered and made other editorial updates.
Now a WG document, future versions could re-introduce some of the
material from the initial submission, but in a more concrete form.</t>
    </note>
  </front>
  <middle>
    <section anchor="intro" numbered="true" toc="default">
      <name>Introduction</name>
      <t>The Concise Binary Object Representation (CBOR, <xref target="RFC8949" format="default"/>) provides
for the interchange of structured data without a requirement for a
pre-agreed schema.
RFC 8949 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.</t>
      <t>(TBD: Expand on text from abstract here.)</t>
      <section anchor="terms" numbered="true" toc="default">
        <name>Terminology</name>
        <t>The key words "<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL</bcp14>
NOT", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>",
"<bcp14>MAY</bcp14>", and "<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as
described in BCP&nbsp;14 <xref target="RFC2119" format="default"/> <xref target="RFC8174" format="default"/> when, and only when, they
appear in all capitals, as shown here.</t>
        <t>The term "byte" is used in its now customary sense as a synonym for
"octet".
Where bit arithmetic is explained, this document uses the notation
familiar from the programming language C (including C++14's 0bnnn
binary literals), except that the operator "**" stands for
exponentiation.</t>
      </section>
    </section>
    <section anchor="objectives" numbered="true" toc="default">
      <name>Objectives</name>
      <t>For the time tag,
the present specification addresses the following objectives that go
beyond the original tags 0 and 1:</t>
      <ul spacing="normal">
        <li>Additional resolution for epoch-based time (as in tag 1).  CBOR tag
1 only provides for integer and up to binary64 floating point
representation of times, limiting resolution to approximately
microseconds at the time of writing (and progressively becoming
worse over time).</li>
        <li>Indication of time scale.  Tags 0 and 1 are for UTC; however, some
interchanges are better performed on TAI.  Other time scales may be
registered once they become relevant (e.g., one of the proposed
successors to UTC that might no longer use leap seconds, or a
scale based on smeared leap seconds).</li>
      </ul>
      <t>Not currently addressed, but possibly covered by the definition of
additional map keys for the map inside the tag:</t>
      <ul spacing="normal">
        <li>Direct representation of natural platform time formats.  Some
platforms use epoch-based time formats that require some computation
to convert them into the representations allowed by tag 1; these
computations can also lose precision and cause ambiguities.
(TBD: The present specification does not take a position on whether tag 1 can be
"fixed" to include, e.g., Decimal or BigFloat representations.  It
does define how to use these with the extended time format.)</li>
        <li>Additional indication of intents about the interpretation of the
time given, in particular for future times.
Intents might include information about time zones, daylight savings
times, etc.
<!--
(TBD: This is not yet a well-developed part of the spec; there needs
to be some effort to avoid the kitchen sink.)
-->
        </li>
      </ul>
      <t>Additional tags are defined for durations and periods.</t>
    </section>
    <section anchor="time-format" numbered="true" toc="default">
      <name>Time Format</name>
      <t>An extended time is indicated by CBOR tag 1001, which tags a map data
item (CBOR major type 5).  The map may contain integer (major types 0
and 1) or text string (major type 3) keys, with the value type
determined by each specific key.   Implementations <bcp14>MUST</bcp14> ignore
key/value types they do not understand for negative integer and text
string values of the key.
Not understanding key/value for unsigned keys is an error.
<!-- (Discussion: Do we need "critical" keys?) -->
      </t>
      <t>The map must contain exactly one unsigned integer key, which
specifies the "base time", and may also contain one or more negative
integer or text-string keys, which may encode supplementary
information such as:</t>
      <ul spacing="normal">
        <li>a higher precision time offset to be added to the base time,</li>
        <li>a reference time scale and epoch different from the default UTC and 1970-01-01</li>
        <li>information about clock quality parameters, such as source,
accuracy, and uncertainty
<!-- precision, and resolution -->
        </li>
      </ul>
      <t>Future keys may add:</t>
      <ul spacing="normal">
        <li>intent information such as timezone and daylight savings time,
and/or possibly positioning coordinates, to express information that
would indicate a local time.</li>
      </ul>
      <t>While this document does not define supplementary text keys, a number
of unsigned and negative-integer keys are defined below.</t>
      <section anchor="key-1" numbered="true" toc="default">
        <name>Key 1</name>
        <t>Key 1 indicates a value that is exactly like the data item that would
be tagged by CBOR tag 1 (Posix time <xref target="TIME_T" format="default"/> as int or float).
The time value indicated by the value under this key can be further
modified by other keys.</t>
      </section>
      <section anchor="keys-4-and-5" numbered="true" toc="default">
        <name>Keys 4 and 5</name>
        <t>Keys 4 and 5 are like key 1, except that the data item is an array as
defined for CBOR tag 4 or 5, respectively.  This can be used to include
a Decimal or Bigfloat epoch-based float <xref target="TIME_T" format="default"/> in an extended time.</t>
      </section>
      <section anchor="keys-3-6-9-12-15-18" numbered="true" toc="default">
        <name>Keys -3, -6, -9, -12, -15, -18</name>
        <t>The keys -3, -6, -9, -12, -15 and -18 indicate additional decimal fractions by
giving an unsigned integer (major type 0) and scaling this with the
scale factor 1e-3, 1e-6, 1e-9, 1e-12, 1e-15, and 1e-18, respectively (see <xref target="decfract" format="default"/>).  More than one
of these keys <bcp14>MUST NOT</bcp14> be present in one extended time data item.
These additional fractions are added to a base time in seconds <xref target="SI-SECOND" format="default"/>
indicated by a Key 1, which then <bcp14>MUST</bcp14> also be present and <bcp14>MUST</bcp14> have an
integer value.</t>
        <table anchor="decfract" align="center">
          <name>Key for decimally scaled Fractions</name>
          <thead>
            <tr>
              <th align="left">Key</th>
              <th align="left">meaning</th>
              <th align="left">example usage</th>
            </tr>
          </thead>
          <tbody>
            <tr>
              <td align="left">-3</td>
              <td align="left">milliseconds</td>
              <td align="left">Java time</td>
            </tr>
            <tr>
              <td align="left">-6</td>
              <td align="left">microseconds</td>
              <td align="left">(old) UNIX time</td>
            </tr>
            <tr>
              <td align="left">-9</td>
              <td align="left">nanoseconds</td>
              <td align="left">(new) UNIX time</td>
            </tr>
            <tr>
              <td align="left">-12</td>
              <td align="left">picoseconds</td>
              <td align="left">Haskell time</td>
            </tr>
            <tr>
              <td align="left">-15</td>
              <td align="left">femtoseconds</td>
              <td align="left">(future)</td>
            </tr>
            <tr>
              <td align="left">-18</td>
              <td align="left">attoseconds</td>
              <td align="left">(future)</td>
            </tr>
          </tbody>
        </table>
      </section>
      <section anchor="key-timescale" numbered="true" toc="default">
        <name>Key -1: Time Scale</name>
        <t>Key -1 is used to indicate a time scale.  The value 0 indicates UTC,
with the POSIX epoch <xref target="TIME_T" format="default"/>; the value 1 indicates TAI, with the
PTP (Precision Time Protocol) epoch <xref target="IEEE1588-2008" format="default"/>.</t>
        <t>If key -1 is not present, time scale value 0 is implied.
Additional values can be registered in the (TBD define name for time
scale registry); values <bcp14>MUST</bcp14> be integers or text strings.</t>
        <t>(Note that there should be no time scales "GPS" or "NTP" -- instead,
the time should be converted to TAI or UTC using a single addition or subtraction.)</t>
        <figure anchor="offset">
          <name>Converting Common Offset Time Scales</name>
          <artset>
            <artwork type="svg" name="" align="left" alt=""><svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" height="6.009ex" role="img" viewBox="0 -791.3 43055.4 2587.3" width="100ex">
                <defs>
                  <path d="M283 438l-10 -38h-70l-78 -320c-1 -3 -2 -8 -2 -11c0 -6 3 -12 16 -12c0 0 23 2 60 52l13 -11c-24 -31 -74 -107 -133 -107c-31 0 -39 25 -39 52c0 13 2 26 5 37l81 320h-77l5 29c75 14 136 51 177 138h13l-31 -129h70Z" id="E1-STIXWEBNORMALI-1D461" stroke-width="1"/>
                  <path d="M444 428l-89 -348c-1 -4 -1 -6 -1 -9c0 -8 4 -14 14 -14c21 0 40 26 57 46l5 6l13 -11c-23 -33 -74 -107 -132 -107c-29 0 -40 19 -40 52c0 9 1 25 4 37l26 95h-1c-7 -5 -97 -126 -137 -156c-23 -17 -49 -28 -72 -28c-47 0 -61 36 -61 74c0 21 3 40 8 59l59 231 c4 15 6 21 6 25c0 12 -11 23 -33 23c-7 0 -19 -1 -26 -3l-3 15l157 26l-84 -326c-2 -9 -3 -16 -3 -24c0 -21 8 -34 26 -34c25 0 65 31 100 77c43 57 89 146 109 219l21 75h77Z" id="E1-STIXWEBNORMALI-1D462" stroke-width="1"/>
                  <path d="M363 111l12 -13c-51 -60 -113 -109 -198 -109c-97 0 -137 78 -137 155c0 140 121 297 263 297c50 0 97 -27 97 -76c0 -38 -16 -70 -54 -70c-26 0 -38 21 -38 38c0 24 29 36 29 58c0 12 -10 21 -34 21c-119 0 -176 -179 -176 -259c0 -87 49 -109 94 -109 c61 0 107 33 142 67Z" id="E1-STIXWEBNORMALI-1D450" stroke-width="1"/>
                  <path d="M637 320h-589v66h589v-66zM637 120h-589v66h589v-66Z" id="E1-STIXWEBMAIN-3D" stroke-width="1"/>
                  <path d="M467 96l-5 -6c-28 -34 -76 -98 -128 -98c-32 0 -41 23 -41 46c0 13 4 29 7 40l57 221c2 8 7 28 7 42c0 19 -6 38 -24 38c-38 0 -101 -86 -132 -133c-36 -54 -62 -101 -68 -122l-33 -124h-77l95 374c0 18 -3 32 -30 32c-10 0 -21 -2 -28 -3l-2 15l159 23l-51 -189h3 c5 0 54 70 56 73c40 50 100 116 160 116c44 0 56 -29 56 -62c0 -25 -6 -50 -11 -70l-59 -231c-1 -2 -1 -5 -1 -10c1 -6 4 -14 15 -14c24 0 48 36 62 53Z" id="E1-STIXWEBNORMALI-1D45B" stroke-width="1"/>
                  <path d="M253 370l14 13c39 37 78 58 113 58c61 0 94 -54 94 -155c0 -129 -110 -298 -254 -298c-24 0 -42 4 -61 19l-24 -100c-3 -13 -5 -24 -5 -35c0 -22 11 -43 61 -43h16l-3 -12h-234l3 12c62 3 69 33 81 79l117 464c0 19 -1 33 -31 33c-8 0 -20 -2 -28 -4l-2 16l158 24 l-18 -69zM214 238l-46 -200c14 -16 34 -21 46 -21c101 0 176 173 176 285c0 63 -28 83 -51 83c-53 0 -105 -61 -125 -147Z" id="E1-STIXWEBNORMALI-1D45D" stroke-width="1"/>
                  <path d="M621 220h-557v66h557v-66Z" id="E1-STIXWEBMAIN-2212" stroke-width="1"/>
                  <path d="M474 137l-54 -137h-391v12l178 189c94 99 130 175 130 260c0 91 -54 141 -139 141c-72 0 -107 -32 -147 -130l-21 5c21 117 85 199 208 199c113 0 185 -77 185 -176c0 -79 -39 -154 -128 -248l-165 -176h234c42 0 63 11 96 67Z" id="E1-STIXWEBMAIN-32" stroke-width="1"/>
                  <path d="M476 330c0 -172 -63 -344 -226 -344c-171 0 -226 186 -226 350c0 177 69 340 230 340c131 0 222 -141 222 -346zM380 325c0 208 -44 325 -132 325c-83 0 -128 -118 -128 -321s44 -317 130 -317c85 0 130 115 130 313Z" id="E1-STIXWEBMAIN-30" stroke-width="1"/>
                  <path d="M445 155c0 -103 -77 -169 -197 -169c-113 0 -192 69 -192 163c0 69 23 108 130 183c-103 85 -124 123 -124 188c0 96 83 156 194 156c99 0 168 -65 168 -143c0 -75 -35 -109 -134 -162c123 -82 155 -136 155 -216zM355 533c0 69 -41 115 -109 115 c-67 0 -110 -37 -110 -99s37 -108 125 -160c68 40 94 82 94 144zM271 272l-59 40c-59 -48 -80 -89 -80 -154c0 -92 51 -144 127 -144c65 0 110 45 110 110c0 62 -30 102 -98 148Z" id="E1-STIXWEBMAIN-38" stroke-width="1"/>
                  <path d="M59 -22l-3 20c152 27 264 132 304 296c-43 -42 -91 -57 -150 -57c-108 0 -180 81 -180 203c0 135 89 236 208 236c64 0 118 -28 157 -76c40 -50 64 -122 64 -206c0 -115 -40 -224 -120 -297c-85 -77 -150 -101 -280 -119zM362 355v39c0 168 -45 254 -132 254 c-30 0 -56 -12 -73 -34c-20 -27 -35 -86 -35 -140c0 -119 48 -194 123 -194c44 0 117 22 117 75Z" id="E1-STIXWEBMAIN-39" stroke-width="1"/>
                  <path d="M472 428l-91 -345s-1 -2 -1 -11c0 -11 6 -17 14 -17c10 0 25 2 64 54l12 -12c-31 -47 -85 -107 -133 -107c-33 0 -42 23 -42 55c0 13 6 34 11 50h-4c-72 -92 -134 -105 -173 -105c-63 0 -89 55 -89 119c0 132 132 332 276 332c43 0 64 -24 66 -46h1l9 33h80zM367 341 c0 41 -12 71 -50 71c-68 0 -128 -87 -162 -171c-18 -45 -28 -89 -28 -124c0 -53 31 -66 58 -66c69 0 139 95 167 190c8 26 15 66 15 100Z" id="E1-STIXWEBNORMALI-1D44E" stroke-width="1"/>
                  <path d="M257 566c0 -26 -22 -46 -48 -46c-29 0 -48 20 -48 46c0 25 19 50 48 50c26 0 48 -25 48 -50zM227 441l-92 -364c-1 -6 -1 -10 -1 -14c0 -7 6 -10 13 -10c22 0 28 12 64 51l13 -10c-35 -45 -85 -105 -134 -105c-28 0 -40 19 -40 46c0 12 0 31 79 338c1 2 2 9 2 12 c0 17 -8 22 -31 22c-9 0 -21 -2 -28 -4l-3 16Z" id="E1-STIXWEBNORMALI-1D456" stroke-width="1"/>
                  <path d="M492 413l-13 -45h-81c13 -15 17 -28 17 -50c0 -75 -53 -137 -141 -148c-59 -8 -88 -33 -88 -58c0 -63 233 -23 233 -148c0 -71 -66 -151 -215 -151c-134 0 -184 57 -184 115s55 88 117 108c-17 11 -24 30 -24 47c0 38 37 87 85 87v4c-67 15 -94 62 -94 109 c0 79 68 158 174 158c42 0 73 -13 88 -28h126zM336 349c0 37 -10 62 -54 62c-54 0 -98 -71 -98 -139c0 -46 12 -81 56 -81c71 0 96 102 96 158zM349 -69c0 78 -132 73 -192 95c-8 -5 -18 -10 -26 -16c-26 -19 -48 -45 -48 -72c0 -47 44 -97 139 -97c91 0 127 46 127 90Z" id="E1-STIXWEBNORMALI-1D454" stroke-width="1"/>
                  <path d="M390 441l-24 -146h-15c0 64 -36 120 -92 120c-25 0 -51 -17 -51 -58c0 -55 134 -147 134 -242c0 -62 -48 -125 -135 -125c-34 0 -98 20 -110 20c-9 0 -18 -4 -30 -21h-17l25 156h16c0 -63 41 -130 104 -130c59 0 73 50 73 89c0 82 -130 132 -130 230c0 79 59 107 114 107 c43 0 63 -20 92 -20c11 0 22 10 30 20h16Z" id="E1-STIXWEBNORMALI-1D460" stroke-width="1"/>
                  <path d="M636 220h-261v-261h-66v261h-261v66h261v261h66v-261h261v-66Z" id="E1-STIXWEBMAIN-2B" stroke-width="1"/>
                  <path d="M61 510l-16 4c29 95 92 162 196 162c93 0 156 -55 156 -137c0 -48 -26 -98 -93 -138c44 -19 62 -31 83 -53c28 -31 44 -77 44 -129c0 -53 -17 -102 -46 -140c-48 -64 -143 -93 -232 -93c-73 0 -112 21 -112 57c0 21 18 36 41 36c17 0 33 -6 61 -26c37 -26 58 -31 86 -31 c74 0 130 68 130 153c0 76 -35 125 -104 145c-22 7 -45 10 -102 10v14c38 13 64 24 84 36c49 28 81 73 81 134c0 68 -42 102 -108 102c-62 0 -108 -32 -149 -106Z" id="E1-STIXWEBMAIN-33" stroke-width="1"/>
                  <path d="M394 0h-276v15c74 4 95 25 95 80v449c0 34 -9 49 -30 49c-10 0 -27 -5 -45 -12l-27 -10v14l179 91l9 -3v-597c0 -43 20 -61 95 -61v-15Z" id="E1-STIXWEBMAIN-31" stroke-width="1"/>
                  <path d="M438 681l-36 -85c-3 -7 -11 -13 -27 -13h-194l-40 -85c143 -27 193 -49 250 -128c26 -36 35 -74 35 -127c0 -96 -30 -158 -98 -208c-47 -34 -102 -49 -170 -49c-75 0 -127 24 -127 62c0 25 17 38 45 38c23 0 42 -5 74 -31c28 -23 51 -32 71 -32c70 0 135 83 135 169 c0 64 -22 114 -67 150c-47 38 -117 70 -213 70c-9 0 -12 2 -12 8c0 2 1 5 1 5l109 237h207c23 0 32 5 48 26Z" id="E1-STIXWEBMAIN-35" stroke-width="1"/>
                  <path d="M446 684l2 -16c-157 -26 -269 -134 -296 -285c49 38 83 45 127 45c117 0 189 -80 189 -209c0 -64 -18 -120 -51 -160c-37 -46 -93 -73 -159 -73c-79 0 -142 37 -177 101c-28 51 -47 122 -47 192c0 108 38 203 109 276c86 90 165 114 303 129zM378 188 c0 128 -42 194 -135 194c-57 0 -116 -24 -116 -116c0 -152 48 -252 142 -252c72 0 109 72 109 174Z" id="E1-STIXWEBMAIN-36" stroke-width="1"/>
                  <path d="M473 167h-103v-167h-78v167h-280v64l314 445h44v-445h103v-64zM292 231v343l-240 -343h240Z" id="E1-STIXWEBMAIN-34" stroke-width="1"/>
                </defs>
                <g fill="black" stroke="currentColor" stroke-width="0" transform="matrix(1 0 0 -1 0 0)">
                  <g transform="translate(16540,0)">
                    <use xlink:href="#E1-STIXWEBNORMALI-1D461" x="0" y="0"/>
                    <g transform="translate(313,-150)">
                      <use xlink:href="#E1-STIXWEBNORMALI-1D462" transform="scale(0.707)" x="0" y="0"/>
                      <use xlink:href="#E1-STIXWEBNORMALI-1D461" transform="scale(0.707)" x="474" y="0"/>
                      <use xlink:href="#E1-STIXWEBNORMALI-1D450" transform="scale(0.707)" x="788" y="0"/>
                    </g>
                    <use xlink:href="#E1-STIXWEBMAIN-3D" x="1542" y="0"/>
                    <g transform="translate(2505,0)">
                      <use xlink:href="#E1-STIXWEBNORMALI-1D461" x="0" y="0"/>
                      <g transform="translate(313,-150)">
                        <use xlink:href="#E1-STIXWEBNORMALI-1D45B" transform="scale(0.707)" x="0" y="0"/>
                        <use xlink:href="#E1-STIXWEBNORMALI-1D461" transform="scale(0.707)" x="497" y="0"/>
                        <use xlink:href="#E1-STIXWEBNORMALI-1D45D" transform="scale(0.707)" x="810" y="0"/>
                      </g>
                    </g>
                    <use xlink:href="#E1-STIXWEBMAIN-2212" x="4060" y="0"/>
                    <g transform="translate(4968,0)">
                      <use xlink:href="#E1-STIXWEBMAIN-32"/>
                      <use xlink:href="#E1-STIXWEBMAIN-32" x="500" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-30" x="1001" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-38" x="1501" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-39" x="2002" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-38" x="2502" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-38" x="3003" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-38" x="3503" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-30" x="4004" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-30" x="4504" y="0"/>
                    </g>
                  </g>
                  <g transform="translate(16774,-1400)">
                    <use xlink:href="#E1-STIXWEBNORMALI-1D461" x="0" y="0"/>
                    <g transform="translate(313,-150)">
                      <use xlink:href="#E1-STIXWEBNORMALI-1D461" transform="scale(0.707)" x="0" y="0"/>
                      <use xlink:href="#E1-STIXWEBNORMALI-1D44E" transform="scale(0.707)" x="313" y="0"/>
                      <use xlink:href="#E1-STIXWEBNORMALI-1D456" transform="scale(0.707)" x="816" y="0"/>
                    </g>
                    <use xlink:href="#E1-STIXWEBMAIN-3D" x="1488" y="0"/>
                    <g transform="translate(2451,0)">
                      <use xlink:href="#E1-STIXWEBNORMALI-1D461" x="0" y="0"/>
                      <g transform="translate(313,-150)">
                        <use xlink:href="#E1-STIXWEBNORMALI-1D454" transform="scale(0.707)" x="0" y="0"/>
                        <use xlink:href="#E1-STIXWEBNORMALI-1D45D" transform="scale(0.707)" x="492" y="0"/>
                        <use xlink:href="#E1-STIXWEBNORMALI-1D460" transform="scale(0.707)" x="982" y="0"/>
                      </g>
                    </g>
                    <use xlink:href="#E1-STIXWEBMAIN-2B" x="4093" y="0"/>
                    <g transform="translate(5001,0)">
                      <use xlink:href="#E1-STIXWEBMAIN-33"/>
                      <use xlink:href="#E1-STIXWEBMAIN-31" x="500" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-35" x="1001" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-39" x="1501" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-36" x="2002" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-34" x="2502" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-38" x="3003" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-31" x="3503" y="0"/>
                      <use xlink:href="#E1-STIXWEBMAIN-39" x="4004" y="0"/>
                    </g>
                  </g>
                </g>
              </svg>
            </artwork>
            <artwork type="ascii-art" name="" align="left" alt=""><![CDATA[t    = t    - 2208988800
 utc    ntp

t    = t    + 315964819
 tai    gps
]]></artwork>
          </artset>
        </figure>
      </section>
      <section anchor="clock-quality" numbered="true" toc="default">
        <name>Clock Quality</name>
        <t>A number of keys are defined to indicate the quality of clock that was
used to determine the point in time.</t>
        <t>The first three are analogous to <tt>clock-quality-grouping</tt> in
<xref target="RFC8575" format="default"/>, which is in turn based on the definitions in
<xref target="IEEE1588-2008" format="default"/>; two more are specific to this document.</t>
        <sourcecode type="cddl">
ClockQuality-group = (
  ? ClockClass =&gt; uint .size 1 ; PTP/RFC8575
  ? ClockAccuracy =&gt; uint .size 1 ; PTP/RFC8575
  ? OffsetScaledLogVariance =&gt; uint .size 2 ; PTP/RFC8575
  ? Uncertainty =&gt; ~time/~duration
  ? Guarantee =&gt; ~time/~duration
)
ClockClass = -2
ClockAccuracy = -4
OffsetScaledLogVariance = -5
Uncertainty = -7
Guarantee = -8
</sourcecode>
        <section anchor="clockclass-key-2" numbered="true" toc="default">
          <name>ClockClass (Key -2)</name>
          <t>Key -2 (ClockClass) can be used to indicate the clock class as per
Table 5 of <xref target="IEEE1588-2008" format="default"/>.
It is defined as a one-byte unsigned integer as that is the range defined there.</t>
        </section>
        <section anchor="clockaccuracy-key-4" numbered="true" toc="default">
          <name>ClockAccuracy (Key -4)</name>
          <t>Key -4 (ClockAccuracy) can be used to indicate the clock accuracy as per
Table 6 of <xref target="IEEE1588-2008" format="default"/>.
It is defined as a one-byte unsigned integer as that is the range defined there.
The range between 32 and 47 is a slightly distorted logarithmic scale from
25&nbsp;ns to 1&nbsp;s (see <xref target="formula-accuracy-enum" format="default"/>); the number 254 is the
value to be used if an unknown accuracy needs to be expressed.</t>
          <figure anchor="formula-accuracy-enum">
            <name>Approximate conversion from accuracy to accuracy enumeration value</name>
            <artset>
              <artwork type="svg" name="" align="left" alt=""><svg xmlns:xlink="http://www.w3.org/1999/xlink" xmlns="http://www.w3.org/2000/svg" height="4.676ex" role="img" viewBox="0 -1221.9 14044.6 2013.3" width="32.62ex">
                  <defs>
                    <path d="M363 112l14 -13c-70 -86 -138 -110 -200 -110c-98 0 -137 84 -137 156c0 23 1 37 6 60c25 111 135 236 262 236c42 0 102 -14 102 -76c0 -127 -167 -176 -286 -182v-28c0 -64 52 -107 113 -107c42 0 90 18 126 64zM124 211h9c104 0 198 69 198 157c0 25 -19 43 -44 43 c-74 0 -134 -115 -163 -200Z" id="E1-STIXWEBNORMALI-1D452" stroke-width="1"/>
                    <path d="M467 96l-5 -6c-28 -34 -76 -98 -128 -98c-32 0 -41 23 -41 46c0 13 4 29 7 40l57 221c2 8 7 28 7 42c0 19 -6 38 -24 38c-38 0 -101 -86 -132 -133c-36 -54 -62 -101 -68 -122l-33 -124h-77l95 374c0 18 -3 32 -30 32c-10 0 -21 -2 -28 -3l-2 15l159 23l-51 -189h3 c5 0 54 70 56 73c40 50 100 116 160 116c44 0 56 -29 56 -62c0 -25 -6 -50 -11 -70l-59 -231c-1 -2 -1 -5 -1 -10c1 -6 4 -14 15 -14c24 0 48 36 62 53Z" id="E1-STIXWEBNORMALI-1D45B" stroke-width="1"/>
                    <path d="M444 428l-89 -348c-1 -4 -1 -6 -1 -9c0 -8 4 -14 14 -14c21 0 40 26 57 46l5 6l13 -11c-23 -33 -74 -107 -132 -107c-29 0 -40 19 -40 52c0 9 1 25 4 37l26 95h-1c-7 -5 -97 -126 -137 -156c-23 -17 -49 -28 -72 -28c-47 0 -61 36 -61 74c0 21 3 40 8 59l59 231 c4 15 6 21 6 25c0 12 -11 23 -33 23c-7 0 -19 -1 -26 -3l-3 15l157 26l-84 -326c-2 -9 -3 -16 -3 -24c0 -21 8 -34 26 -34c25 0 65 31 100 77c43 57 89 146 109 219l21 75h77Z" id="E1-STIXWEBNORMALI-1D462" stroke-width="1"/>
                    <path d="M667 107l13 -11c-32 -54 -84 -104 -131 -104c-22 0 -39 10 -39 49c0 7 1 17 6 37l56 221c4 14 6 23 6 40c0 20 -6 38 -24 38c-54 0 -164 -181 -179 -242l-34 -135h-79l77 299c2 9 5 25 5 40c0 20 -5 38 -23 38c-52 0 -162 -181 -178 -242l-35 -135h-78l95 374 c0 18 -6 31 -33 31c-8 0 -19 -1 -27 -2l-2 14l157 24l-44 -169h6c94 143 154 169 192 169c37 0 55 -37 55 -81c0 -17 -3 -32 -9 -52l-10 -36h5c29 52 81 114 130 147c22 15 41 22 61 22c36 0 54 -26 54 -71c0 -18 -1 -37 -7 -61l-61 -231c-1 -3 -2 -9 -2 -12 c0 -8 6 -12 15 -12c17 0 43 16 62 53Z" id="E1-STIXWEBNORMALI-1D45A" stroke-width="1"/>
                    <path d="M472 428l-91 -345s-1 -2 -1 -11c0 -11 6 -17 14 -17c10 0 25 2 64 54l12 -12c-31 -47 -85 -107 -133 -107c-33 0 -42 23 -42 55c0 13 6 34 11 50h-4c-72 -92 -134 -105 -173 -105c-63 0 -89 55 -89 119c0 132 132 332 276 332c43 0 64 -24 66 -46h1l9 33h80zM367 341 c0 41 -12 71 -50 71c-68 0 -128 -87 -162 -171c-18 -45 -28 -89 -28 -124c0 -53 31 -66 58 -66c69 0 139 95 167 190c8 26 15 66 15 100Z" id="E1-STIXWEBNORMALI-1D44E" stroke-width="1"/>
                    <path d="M363 111l12 -13c-51 -60 -113 -109 -198 -109c-97 0 -137 78 -137 155c0 140 121 297 263 297c50 0 97 -27 97 -76c0 -38 -16 -70 -54 -70c-26 0 -38 21 -38 38c0 24 29 36 29 58c0 12 -10 21 -34 21c-119 0 -176 -179 -176 -259c0 -87 49 -109 94 -109 c61 0 107 33 142 67Z" id="E1-STIXWEBNORMALI-1D450" stroke-width="1"/>
                    <path d="M604 475h33c-6 -85 -60 -204 -158 -204c-96 0 -203 128 -275 128c-70 0 -107 -67 -123 -138h-33c5 100 65 204 163 204c96 0 203 -128 276 -128c69 0 102 67 117 138zM604 239h33c-6 -85 -60 -204 -158 -204c-96 0 -203 128 -275 128c-70 0 -107 -67 -123 -138h-33 c5 100 65 204 163 204c96 0 203 -128 276 -128c69 0 102 67 117 138Z" id="E1-STIXWEBMAIN-2248" stroke-width="1"/>
                    <path d="M473 167h-103v-167h-78v167h-280v64l314 445h44v-445h103v-64zM292 231v343l-240 -343h240Z" id="E1-STIXWEBMAIN-34" stroke-width="1"/>
                    <path d="M445 155c0 -103 -77 -169 -197 -169c-113 0 -192 69 -192 163c0 69 23 108 130 183c-103 85 -124 123 -124 188c0 96 83 156 194 156c99 0 168 -65 168 -143c0 -75 -35 -109 -134 -162c123 -82 155 -136 155 -216zM355 533c0 69 -41 115 -109 115 c-67 0 -110 -37 -110 -99s37 -108 125 -160c68 40 94 82 94 144zM271 272l-59 40c-59 -48 -80 -89 -80 -154c0 -92 51 -144 127 -144c65 0 110 45 110 110c0 62 -30 102 -98 148Z" id="E1-STIXWEBMAIN-38" stroke-width="1"/>
                    <path d="M636 220h-261v-261h-66v261h-261v66h261v261h66v-261h261v-66Z" id="E1-STIXWEBMAIN-2B" stroke-width="1"/>
                    <path d="M447 -213h-259v926h66v-798c0 -64 19 -95 84 -95h109v-33Z" id="E1-STIXWEBMAIN-230A" stroke-width="1"/>
                    <path d="M474 137l-54 -137h-391v12l178 189c94 99 130 175 130 260c0 91 -54 141 -139 141c-72 0 -107 -32 -147 -130l-21 5c21 117 85 199 208 199c113 0 185 -77 185 -176c0 -79 -39 -154 -128 -248l-165 -176h234c42 0 63 11 96 67Z" id="E1-STIXWEBMAIN-32" stroke-width="1"/>
                    <path d="M203 253c0 -32 -27 -60 -59 -60c-33 0 -61 30 -61 60s28 60 61 60c32 0 59 -28 59 -60Z" id="E1-STIXWEBMAIN-22C5" stroke-width="1"/>
                    <path d="M278 668l-148 -591s-1 -4 -1 -11s4 -13 12 -13c23 0 53 39 62 55l16 -12c-34 -40 -77 -106 -135 -106c-30 0 -39 26 -39 51c0 12 3 26 6 36l128 510c3 13 3 21 3 24c0 12 -8 22 -31 22c-7 0 -19 -2 -27 -3l-3 15Z" id="E1-STIXWEBNORMALI-1D459" stroke-width="1"/>
                    <path d="M438 287c0 -139 -110 -298 -263 -298c-101 0 -135 90 -135 163c0 128 103 289 251 289c80 0 147 -46 147 -154zM357 318c0 38 -14 93 -67 93c-82 0 -169 -149 -169 -285c0 -33 3 -107 59 -107c106 0 177 223 177 299Z" id="E1-STIXWEBNORMALI-1D45C" stroke-width="1"/>
                    <path d="M492 413l-13 -45h-81c13 -15 17 -28 17 -50c0 -75 -53 -137 -141 -148c-59 -8 -88 -33 -88 -58c0 -63 233 -23 233 -148c0 -71 -66 -151 -215 -151c-134 0 -184 57 -184 115s55 88 117 108c-17 11 -24 30 -24 47c0 38 37 87 85 87v4c-67 15 -94 62 -94 109 c0 79 68 158 174 158c42 0 73 -13 88 -28h126zM336 349c0 37 -10 62 -54 62c-54 0 -98 -71 -98 -139c0 -46 12 -81 56 -81c71 0 96 102 96 158zM349 -69c0 78 -132 73 -192 95c-8 -5 -18 -10 -26 -16c-26 -19 -48 -45 -48 -72c0 -47 44 -97 139 -97c91 0 127 46 127 90Z" id="E1-STIXWEBNORMALI-1D454" stroke-width="1"/>
                    <path d="M394 0h-276v15c74 4 95 25 95 80v449c0 34 -9 49 -30 49c-10 0 -27 -5 -45 -12l-27 -10v14l179 91l9 -3v-597c0 -43 20 -61 95 -61v-15Z" id="E1-STIXWEBMAIN-31" stroke-width="1"/>
                    <path d="M476 330c0 -172 -63 -344 -226 -344c-171 0 -226 186 -226 350c0 177 69 340 230 340c131 0 222 -141 222 -346zM380 325c0 208 -44 325 -132 325c-83 0 -128 -118 -128 -321s44 -317 130 -317c85 0 130 115 130 313Z" id="E1-STIXWEBMAIN-30" stroke-width="1"/>
                    <path d="M156 301l104 -63c64 -39 88 -66 88 -123c0 -67 -64 -125 -140 -125c-21 0 -50 1 -73 9c-24 8 -35 9 -46 9c-12 0 -18 -2 -24 -12h-13v157h16c21 -97 58 -141 127 -141c51 0 83 33 83 74c0 31 -20 57 -53 75l-54 30c-83 46 -120 94 -120 145c0 79 56 123 138 123 c24 0 46 -1 67 -11c11 -5 21 -8 28 -8c4 0 8 1 16 10h11l5 -136h-15c-23 90 -53 123 -113 123c-43 0 -75 -21 -75 -68c0 -22 15 -51 43 -68Z" id="E1-STIXWEBMAIN-73" stroke-width="1"/>
                    <path d="M621 220h-557v66h557v-66Z" id="E1-STIXWEBMAIN-2212" stroke-width="1"/>
                    <path d="M430 441l-19 -132h-15c-7 46 -24 105 -93 105c-82 0 -139 -97 -161 -167h181l-5 -36h-185c-7 -20 -7 -41 -7 -66c0 -64 37 -101 92 -101c58 0 109 34 144 68l12 -14c-53 -60 -111 -109 -194 -109c-94 0 -140 69 -140 152c0 142 114 300 269 300c49 0 55 -20 83 -20 c12 0 19 11 23 20h15Z" id="E1-STIXWEBNORMALI-1D716" stroke-width="1"/>
                    <path d="M286 -213h-259v33h109c65 0 84 31 84 95v798h66v-926Z" id="E1-STIXWEBMAIN-230B" stroke-width="1"/>
                  </defs>
                  <g fill="black" stroke="currentColor" stroke-width="0" transform="matrix(1 0 0 -1 0 0)">
                    <use xlink:href="#E1-STIXWEBNORMALI-1D452" x="0" y="0"/>
                    <use xlink:href="#E1-STIXWEBNORMALI-1D45B" x="445" y="0"/>
                    <use xlink:href="#E1-STIXWEBNORMALI-1D462" x="943" y="0"/>
                    <g transform="translate(1417,0)">
                      <use xlink:href="#E1-STIXWEBNORMALI-1D45A" x="0" y="0"/>
                      <g transform="translate(710,-150)">
                        <use xlink:href="#E1-STIXWEBNORMALI-1D44E" transform="scale(0.707)" x="0" y="0"/>
                        <use xlink:href="#E1-STIXWEBNORMALI-1D450" transform="scale(0.707)" x="502" y="0"/>
                        <use xlink:href="#E1-STIXWEBNORMALI-1D450" transform="scale(0.707)" x="918" y="0"/>
                      </g>
                    </g>
                    <use xlink:href="#E1-STIXWEBMAIN-2248" x="3448" y="0"/>
                    <g transform="translate(4411,0)">
                      <use xlink:href="#E1-STIXWEBMAIN-34"/>
                      <use xlink:href="#E1-STIXWEBMAIN-38" x="500" y="0"/>
                    </g>
                    <use xlink:href="#E1-STIXWEBMAIN-2B" x="5635" y="0"/>
                    <use xlink:href="#E1-STIXWEBMAIN-230A" x="6542" y="0"/>
                    <use xlink:href="#E1-STIXWEBMAIN-32" x="7012" y="0"/>
                    <use xlink:href="#E1-STIXWEBMAIN-22C5" x="7735" y="0"/>
                    <use xlink:href="#E1-STIXWEBNORMALI-1D459" x="8243" y="0"/>
                    <use xlink:href="#E1-STIXWEBNORMALI-1D45C" x="8562" y="0"/>
                    <g transform="translate(9020,0)">
                      <use xlink:href="#E1-STIXWEBNORMALI-1D454" x="0" y="0"/>
                      <g transform="translate(492,-150)">
                        <use xlink:href="#E1-STIXWEBMAIN-31" transform="scale(0.707)"/>
                        <use xlink:href="#E1-STIXWEBMAIN-30" transform="scale(0.707)" x="500" y="0"/>
                      </g>
                    </g>
                    <g transform="translate(10321,0)">
                      <g transform="translate(120,0)">
                        <rect height="60" width="1453" x="0" y="220"/>
                        <g transform="translate(60,676)">
                          <use xlink:href="#E1-STIXWEBNORMALI-1D44E" x="0" y="0"/>
                          <use xlink:href="#E1-STIXWEBNORMALI-1D450" x="502" y="0"/>
                          <use xlink:href="#E1-STIXWEBNORMALI-1D450" x="918" y="0"/>
                        </g>
                        <use xlink:href="#E1-STIXWEBMAIN-73" x="532" y="-686"/>
                      </g>
                    </g>
                    <use xlink:href="#E1-STIXWEBMAIN-2212" x="12236" y="0"/>
                    <use xlink:href="#E1-STIXWEBNORMALI-1D716" x="13144" y="0"/>
                    <use xlink:href="#E1-STIXWEBMAIN-230B" x="13575" y="0"/>
                  </g>
                </svg>
              </artwork>
              <artwork type="ascii-art" name="" align="left" alt=""><![CDATA[enum   approx48 + |_2cdotlog  {accovers} - epsilon_|
    acc                     10
]]></artwork>
            </artset>
          </figure>
        </section>
        <section anchor="offsetscaledlogvariance-key-5" numbered="true" toc="default">
          <name>OffsetScaledLogVariance (Key -5)</name>
          <t>Key -5 (OffsetScaledLogVariance) can be used to represent the variance
exhibited by the clock when it has lost its synchronization with an
external reference clock.  The details for the computation of this
characteristic are defined in Section 7.6.3 of <xref target="IEEE1588-2008" format="default"/>.</t>
        </section>
        <section anchor="uncertainty-key-7" numbered="true" toc="default">
          <name>Uncertainty (Key -7)</name>
          <t>Key -7 (Uncertainty) can be used to represent a known measurement
uncertainty for the clock, as a numeric value in seconds or as a
duration (<xref target="duration" format="default"/>).</t>
          <t>For this document, uncertainty is defined as in Section 2.2.3 of
<xref target="GUM" format="default"/>: "parameter, associated with the result of a measurement, that
characterizes the dispersion of the values that could reasonably be
attributed to the measurand".  More specifically, the value for this
key represents the extended uncertainty for k&nbsp;=&nbsp;2, in seconds.</t>
        </section>
        <section anchor="guarantee-key-8" numbered="true" toc="default">
          <name>Guarantee (Key -8)</name>
          <t>Key -8 (Guarantee) can be used to represent a stated guarantee for the
accuracy of the point in time, as a numeric value in seconds or as a
duration (<xref target="duration" format="default"/>)
representing the maximum allowed deviation from the true value.</t>
          <t>While such a guarantee is unattainable in theory, existing standards
such as <xref target="RFC3161" format="default"/> stipulate the representation of such guarantees,
and therefore this format provides a way to represent them as well;
the time value given is nominally guaranteed to not deviate from the
actual time by more than the value of the guarantee, in seconds.</t>
        </section>
      </section>
    </section>
    <section anchor="duration" numbered="true" toc="default">
      <name>Duration Format</name>
      <t>A duration is the length of an interval of time.
Durations in this format are given in SI seconds, possibly adjusted
for conventional corrections of the time scale given (e.g., leap
seconds).</t>
      <t>Except for using Tag 1002 instead of 1001,
durations are structurally identical to time values.
Semantically, they do not measure the time elapsed from a given epoch,
but from the start to the end of (an otherwise unspecified) interval
of time.</t>
      <t>In combination with an epoch identified in the context, a duration can
also be used to express an absolute time.</t>
      <aside>
        <t>(TBD: Clearly, ISO8601 durations are rather different; we do not want to use these.)</t>
      </aside>
    </section>
    <section anchor="period" numbered="true" toc="default">
      <name>Period Format</name>
      <t>A period is a specific interval of time, specified as either two times
giving the start and the end of that interval, or as one of these two
plus a duration.</t>
      <t>They are given as an array of unwrapped time and duration elements,
tagged with Tag 1003:</t>
      <sourcecode type="cddl">
Period = #6.1003([
  start: ~Time / null
  end: ~Time / null
  ? duration: ~Duration / null
])
</sourcecode>
      <t>If the third array element is not given, the duration element is null.
Exactly two out of the three elements must be non-null, this can be
clumsily expressed in CDDL as:</t>
      <sourcecode type="cddl">
Period = #6.1003([
  (start: ~Time,
   ((end: ~Time,
     ? duration: null) //
    (end: null,
     duration: ~Duration))) //
  (start: null,
   end: ~Time,
   duration: ~Duration)
])
</sourcecode>
      <aside>
        <t>(Issue: should start/end be given the two-element treatment, or start/duration?)</t>
      </aside>
    </section>
    <section anchor="cddl-typenames" numbered="true" toc="default">
      <name>CDDL typenames</name>
      <t>For the use with the CBOR Data Definition Language, CDDL <xref target="RFC8610" format="default"/>, the
type names defined in <xref target="tag-cddl" format="default"/> are recommended:</t>
      <figure anchor="tag-cddl">
        <name>Recommended type names for CDDL</name>
        <sourcecode type="cddl">
etime = #6.1001({* (int/tstr) =&gt; any})
duration = #6.1002({* (int/tstr) =&gt; any})
period = #6.1003([~etime/null, ~etime/null, ~duration/null])
</sourcecode>
      </figure>
    </section>
    <section anchor="iana-considerations" numbered="true" toc="default">
      <name>IANA Considerations</name>
      <t>In the registry <xref target="IANA.cbor-tags" format="default"/>,
IANA has allocated the tags in <xref target="tab-tag-values" format="default"/> from the
FCFS space, with the present document as the specification reference.</t>
      <table anchor="tab-tag-values" align="center">
        <name>Values for Tags</name>
        <thead>
          <tr>
            <th align="right">Tag</th>
            <th align="left">Data Item</th>
            <th align="left">Semantics</th>
          </tr>
        </thead>
        <tbody>
          <tr>
            <td align="right">1001</td>
            <td align="left">map</td>
            <td align="left">[RFCthis] extended time</td>
          </tr>
          <tr>
            <td align="right">1002</td>
            <td align="left">map</td>
            <td align="left">[RFCthis] duration</td>
          </tr>
          <tr>
            <td align="right">1003</td>
            <td align="left">array</td>
            <td align="left">[RFCthis] period</td>
          </tr>
        </tbody>
      </table>
      <t>IANA is requested to change the "Data Item" column for Tag 1003 from
"map" to "array".</t>
      <aside>
        <t>(TBD: Add registry for time scales.
Add registry for map keys and allocation policies for additional keys.)</t>
      </aside>
    </section>
    <section anchor="security-considerations" numbered="true" toc="default">
      <name>Security Considerations</name>
      <t>The security considerations of RFC 8949 apply; the tags introduced
here are not expected to raise security considerations beyond those.</t>
      <t>Time, of course, has significant security considerations; these
include the exploitation of ambiguities where time is security
relevant (e.g., for freshness or in a validity span) or the disclosure
of characteristics of the emitting system (e.g., time zone, or clock
resolution and wall clock offset).</t>
    </section>
  </middle>
  <back>
    <references>
      <name>References</name>
      <references>
        <name>Normative References</name>
        <reference anchor="RFC8949" target="https://www.rfc-editor.org/info/rfc8949">
          <front>
            <title>Concise Binary Object Representation (CBOR)</title>
            <author fullname="C. Bormann" initials="C." surname="Bormann">
              <organization/>
            </author>
            <author fullname="P. Hoffman" initials="P." surname="Hoffman">
              <organization/>
            </author>
            <date month="December" year="2020"/>
            <abstract>
              <t>The Concise Binary Object Representation (CBOR) 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. These design goals make it different from earlier binary serializations such as ASN.1 and MessagePack.</t>
              <t>This document obsoletes RFC 7049, providing editorial improvements, new details, and errata fixes while keeping full compatibility with the interchange format of RFC 7049.  It does not create a new version of the format.</t>
            </abstract>
          </front>
          <seriesInfo name="STD" value="94"/>
          <seriesInfo name="RFC" value="8949"/>
          <seriesInfo name="DOI" value="10.17487/RFC8949"/>
        </reference>
        <reference anchor="TIME_T" target="http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_16">
          <front>
            <title>Vol. 1: Base Definitions, Issue 7</title>
            <author>
              <organization>The Open Group Base Specifications</organization>
            </author>
            <date year="2016"/>
          </front>
          <seriesInfo name="Section 4.15" value="'Seconds Since the Epoch'"/>
          <seriesInfo name="IEEE Std" value="1003.1-2008"/>
          <seriesInfo name="2016" value="Edition"/>
        </reference>
        <reference anchor="SI-SECOND">
          <front>
            <title>Quantities and units — Part 3: Space and time</title>
            <author>
              <organization>International Organization for Standardization (ISO)</organization>
            </author>
            <date year="2006" month="March" day="01"/>
          </front>
          <seriesInfo name="ISO" value="80000-3"/>
        </reference>
        <reference anchor="IEEE1588-2008" target="http://standards.ieee.org/findstds/standard/1588-2008.html">
          <front>
            <title>1588-2008 - IEEE Standard for a Precision Clock Synchronization Protocol for Networked Measurement and Control Systems</title>
            <author>
              <organization>IEEE</organization>
            </author>
            <date year="2008" month="July"/>
          </front>
        </reference>
        <reference anchor="GUM" target="https://www.bipm.org/en/publications/guides/gum.html">
          <front>
            <title>Evaluation of measurement data — Guide to the expression of uncertainty in measurement</title>
            <author>
              <organization>Joint Committee for Guides in Metrology</organization>
            </author>
            <date year="2008" month="September"/>
          </front>
          <seriesInfo name="JCGM" value="100:2008"/>
        </reference>
        <reference anchor="IANA.cbor-tags" target="http://www.iana.org/assignments/cbor-tags">
          <front>
            <title>Concise Binary Object Representation (CBOR) Tags</title>
            <author>
              <organization>IANA</organization>
            </author>
            <date/>
          </front>
        </reference>
        <reference anchor="RFC8610" target="https://www.rfc-editor.org/info/rfc8610">
          <front>
            <title>Concise Data Definition Language (CDDL): A Notational Convention to Express Concise Binary Object Representation (CBOR) and JSON Data Structures</title>
            <author fullname="H. Birkholz" initials="H." surname="Birkholz">
              <organization/>
            </author>
            <author fullname="C. Vigano" initials="C." surname="Vigano">
              <organization/>
            </author>
            <author fullname="C. Bormann" initials="C." surname="Bormann">
              <organization/>
            </author>
            <date month="June" year="2019"/>
            <abstract>
              <t>This document proposes a notational convention to express Concise Binary Object Representation (CBOR) data structures (RFC 7049).  Its main goal is to provide an easy and unambiguous way to express structures for protocol messages and data formats that use CBOR or JSON.</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8610"/>
          <seriesInfo name="DOI" value="10.17487/RFC8610"/>
        </reference>
        <reference anchor="RFC2119" target="https://www.rfc-editor.org/info/rfc2119">
          <front>
            <title>Key words for use in RFCs to Indicate Requirement Levels</title>
            <author fullname="S. Bradner" initials="S." surname="Bradner">
              <organization/>
            </author>
            <date month="March" year="1997"/>
            <abstract>
              <t>In many standards track documents several words are used to signify the requirements in the specification.  These words are often capitalized. This document defines these words as they should be interpreted in IETF documents.  This document specifies an Internet Best Current Practices for the Internet Community, and requests discussion and suggestions for improvements.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="2119"/>
          <seriesInfo name="DOI" value="10.17487/RFC2119"/>
        </reference>
        <reference anchor="RFC8174" target="https://www.rfc-editor.org/info/rfc8174">
          <front>
            <title>Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words</title>
            <author fullname="B. Leiba" initials="B." surname="Leiba">
              <organization/>
            </author>
            <date month="May" year="2017"/>
            <abstract>
              <t>RFC 2119 specifies common key words that may be used in protocol  specifications.  This document aims to reduce the ambiguity by clarifying that only UPPERCASE usage of the key words have the  defined special meanings.</t>
            </abstract>
          </front>
          <seriesInfo name="BCP" value="14"/>
          <seriesInfo name="RFC" value="8174"/>
          <seriesInfo name="DOI" value="10.17487/RFC8174"/>
        </reference>
      </references>
      <references>
        <name>Informative References</name>
        <reference anchor="RFC8575" target="https://www.rfc-editor.org/info/rfc8575">
          <front>
            <title>YANG Data Model for the Precision Time Protocol (PTP)</title>
            <author fullname="Y. Jiang" initials="Y." role="editor" surname="Jiang">
              <organization/>
            </author>
            <author fullname="X. Liu" initials="X." surname="Liu">
              <organization/>
            </author>
            <author fullname="J. Xu" initials="J." surname="Xu">
              <organization/>
            </author>
            <author fullname="R. Cummings" initials="R." role="editor" surname="Cummings">
              <organization/>
            </author>
            <date month="May" year="2019"/>
            <abstract>
              <t>This document defines a YANG data model for the configuration of devices and clocks using the Precision Time Protocol (PTP) as specified in IEEE Std 1588-2008.  It also defines the retrieval of the configuration information, the data sets and the running states of PTP clocks.  The YANG module in this document conforms to the Network Management Datastore Architecture (NMDA).</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="8575"/>
          <seriesInfo name="DOI" value="10.17487/RFC8575"/>
        </reference>
        <reference anchor="RFC3161" target="https://www.rfc-editor.org/info/rfc3161">
          <front>
            <title>Internet X.509 Public Key Infrastructure Time-Stamp Protocol (TSP)</title>
            <author fullname="C. Adams" initials="C." surname="Adams">
              <organization/>
            </author>
            <author fullname="P. Cain" initials="P." surname="Cain">
              <organization/>
            </author>
            <author fullname="D. Pinkas" initials="D." surname="Pinkas">
              <organization/>
            </author>
            <author fullname="R. Zuccherato" initials="R." surname="Zuccherato">
              <organization/>
            </author>
            <date month="August" year="2001"/>
            <abstract>
              <t>This document describes the format of a request sent to a Time Stamping Authority (TSA) and of the response that is returned.  It also establishes several security-relevant requirements for TSA operation, with regards to processing requests to generate responses.  [STANDARDS-TRACK]</t>
            </abstract>
          </front>
          <seriesInfo name="RFC" value="3161"/>
          <seriesInfo name="DOI" value="10.17487/RFC3161"/>
        </reference>
      </references>
    </references>
    <!--
Contributors
============
{: numbered="no"}

Add reference to [TIME] once available.

Ben Gamari suggested being able to use decimally scaled fractional
seconds in CBOR time.
 -->

<section numbered="false" anchor="acknowledgements" toc="default">
      <name>Acknowledgements</name>
      <!--  LocalWords:  CBOR extensibility IANA uint sint IEEE endian TAI
 -->
<!--  LocalWords:  signedness endianness NTP
 -->

</section>
  </back>
  <!-- ##markdown-source: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-->

</rfc>
