Standards for date / time values?
Blum, Stan
sblum at CALACADEMY.ORG
Thu Feb 23 17:41:04 CET 2006
Hi Lynn,
Context is everything, so I'm going to assume you are talking about date/time
representations in the observation and monitoring schema(s) that you are
developing. The thinking in the collections community has gone something
along the lines of this:
Concept: the date-time of a collecting event [= recording-event,
gathering-event] -- i.e., when one or more organisms were collected or
observed -- expressed in the common Gregorian calendar, in local time.
Requirements:
1 - express the data/time exactly as it was recorded
2 - retreive records by date/time ranges (date-time greater than X and/or
less than Y)
3 - accommodate date-times of varying precision, including explicit date-time
ranges (specifying a duration)
4 - support seasonal (time of year) queries
These requirements can be met by the following fields:
VerbatimDateTime
EarliestDateCollected
LatestDateCollected
CollectingDatesInterpreted
DayOfYear
As John Wieczorek noted, the ISO 8601 format accommodates varying degrees of
precision. Using a "verbatim date-time" [text string] is as good as you can
do to satisfy the first requirement, short of scanning field notes or voice
recordings. The earliest and latest dates support the recording of explicit
ranges as well as interpreted ranges, which could be used to make "Summer of
1952" retrievable. The CollectingDatesInterpreted field would be a boolean
field, set as true when the earliest and latest dates represent
interpretations rather than an explicit range. The "DayOfYear" field is a
compromise that we've offered as a simple way to support queries involving
seasonal (annual) cycles; e.g., collected in the northern summer, regardless
of year. But it can be argued that day of year is derivable from the other
fields (unless year is unknown), and that it doesn't accommodate explicit
ranges.
A bit more documentation is needed to address the odd cases (What do I do
when ...?), but these five fields will support a lot of the data exchange
needed for this concept. These fields are not intended to handle the dating
of localities in paleontology, nor are they intended to handle named periods
that are used in cultural collections (e.g., Iron Age, Victorian).
ABCD uses a few more fields to handle the concept,
http://ww3.bgbm.org/abcddocs/AbcdConcepts
<http://ww3.bgbm.org/abcddocs/AbcdConcepts> but some of these (date, time,
and time zone) are handled by the ISO format, except when the larger units
are unkown; .e.g., the year is unknown, but the day is [ June 16 ]; or the
date is unknown, but the time is [ 14:00-15:30 ].
* AbcdConcept0860 <http://ww3.bgbm.org/abcddocs/AbcdConcept0860>
/DataSets/DataSet/Units/Unit/Gathering/DateTime
* AbcdConcept0861 <http://ww3.bgbm.org/abcddocs/AbcdConcept0861>
/DataSets/DataSet/Units/Unit/Gathering/DateTime/DateText
* AbcdConcept0862 <http://ww3.bgbm.org/abcddocs/AbcdConcept0862>
/DataSets/DataSet/Units/Unit/Gathering/DateTime/TimeZone
* AbcdConcept0863 <http://ww3.bgbm.org/abcddocs/AbcdConcept0863>
/DataSets/DataSet/Units/Unit/Gathering/DateTime/ISODateTimeBegin
* AbcdConcept0864 <http://ww3.bgbm.org/abcddocs/AbcdConcept0864>
/DataSets/DataSet/Units/Unit/Gathering/DateTime/DayNumberBegin
* AbcdConcept0865 <http://ww3.bgbm.org/abcddocs/AbcdConcept0865>
/DataSets/DataSet/Units/Unit/Gathering/DateTime/TimeOfDayBegin
* AbcdConcept0866 <http://ww3.bgbm.org/abcddocs/AbcdConcept0866>
/DataSets/DataSet/Units/Unit/Gathering/DateTime/ISODateTimeEnd
* AbcdConcept0867 <http://ww3.bgbm.org/abcddocs/AbcdConcept0867>
/DataSets/DataSet/Units/Unit/Gathering/DateTime/DayNumberEnd
* AbcdConcept0868 <http://ww3.bgbm.org/abcddocs/AbcdConcept0868>
/DataSets/DataSet/Units/Unit/Gathering/DateTime/TimeOfDayEnd
* AbcdConcept0869 <http://ww3.bgbm.org/abcddocs/AbcdConcept0869>
/DataSets/DataSet/Units/Unit/Gathering/DateTime/PeriodExplicit
The ABCD fields pretty much cover the entire concept space. One could argue
whether time-zone is relevant to the description of biological phenomena, but
we do know that ship trawls do cross time-zones (including the date-line),
and that daylight savings time could stretch or compress some nocturnal
collecting events if their durations were calculated too simply.
To some extent these arguments are still going on, so analyze your
requirements and your data, then state your position. ;-)
Cheers,
-Stan
Stanley D. Blum, Ph.D.
Research Information Manager
California Academy of Sciences
875 Howard St.
San Francisco, CA
+1 (415) 321-8183
-----Original Message-----
From: Taxonomic Databases Working Group List
[mailto:TDWG at LISTSERV.NHM.KU.EDU] On Behalf Of Lynn Kutner
Sent: Thursday, February 23, 2006 9:12 AM
To: TDWG at LISTSERV.NHM.KU.EDU
Subject: Standards for date / time values?
Hi -
I'm working with a suite of date attributes that can include a
combination of precise dates, imprecise dates, and ranges of dates (and the
same types of time values). We'd like to follow existing standards. If this
sort of date / time standard exists, I'd appreciate leads to the appropriate
resources.
Thank you for your help -
Lynn
Lynn Kutner
Data Management Coordinator
NatureServe
Email: lynn_kutner at natureserve.org
Phone: (303) 541-0360
www.natureserve.org <file://www.natureserve.org>
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<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff size=2>Hi
Lynn,</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2>Context is everything, so I'm going to assume you are talking about
date/time representations in the observation and monitoring schema(s) that
you are developing. The thinking in the collections community has gone
something along the lines of this:</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2>Concept: the date-time of a collecting event [= recording-event,
gathering-event] -- i.e., when one or more organisms were collected or observed
-- expressed in the common Gregorian calendar, in local
time.</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2>Requirements: </FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff size=2>1 -
express the data/time exactly as it was recorded</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff size=2>2 -
retreive records by date/time ranges (date-time greater than X and/or less
than Y) </FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff size=2>3 -
accommodate date-times of varying precision, including explicit date-time ranges
(specifying a duration)</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff size=2>4 -
support seasonal (time of year) queries</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff size=2>These
requirements can be met by the following fields:</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2>VerbatimDateTime</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2>EarliestDateCollected</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2>LatestDateCollected</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2>CollectingDatesInterpreted</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2>DayOfYear</FONT></SPAN></DIV></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff size=2>As
John Wieczorek noted, the ISO 8601 format accommodates varying degrees of
precision. Using a "verbatim date-time" [text string] is as good as you
can do to satisfy the first requirement, short of scanning field notes or voice
recordings. The earliest and latest dates support the recording of
explicit ranges as well as interpreted ranges, which could be used to make
"Summer of 1952" retrievable. The CollectingDatesInterpreted field would
be a boolean field, set as true when the earliest and latest dates represent
interpretations rather than an explicit range. The "DayOfYear" field is a
compromise that we've offered as a simple way to support queries involving
seasonal (annual) cycles; e.g., collected in the northern summer, regardless of
year. But it can be argued that day of year is derivable from
the other fields (unless year is unknown), and that it doesn't accommodate
explicit ranges. </FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=607414522-23022006>A bit
more documentation is needed to address the odd cases (What do I do when ...?),
but these five fields will support a lot of the data exchange needed for this
concept. These fields are not intended to handle the dating of localities
in paleontology, nor are they intended to handle named periods that are used in
cultural collections (e.g., Iron Age, Victorian). </SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=607414522-23022006></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2>ABCD uses a <SPAN
class=607414522-23022006>few </SPAN>more fields<SPAN class=607414522-23022006>
to handle the concept</SPAN>, </FONT><A
href="http://ww3.bgbm.org/abcddocs/AbcdConcepts"><FONT face=Arial
size=2>http://ww3.bgbm.org/abcddocs/AbcdConcepts</FONT></A><FONT
face=Arial><FONT color=#0000ff><FONT size=2> <SPAN
class=607414522-23022006> </SPAN></FONT></FONT></FONT></SPAN><SPAN
class=607414522-23022006><FONT face=Arial color=#0000ff size=2>but some of these
(date, time, and time zone) are handled by the ISO format, except when the
larger units are unkown; .e.g., the year is unknown, but the day is [ June 16 ];
or the date is unknown, but the time is [ 14:00-15:30 ].</FONT></SPAN></DIV>
<DIV><SPAN class=607414522-23022006><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=607414522-23022006>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0860">AbcdConcept0860</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime </TT> </P></LI>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0861">AbcdConcept0861</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime/DateText </TT>
</P></LI>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0862">AbcdConcept0862</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime/TimeZone </TT>
</P></LI>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0863">AbcdConcept0863</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime/ISODateTimeBegin </TT>
</P></LI>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0864">AbcdConcept0864</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime/DayNumberBegin </TT>
</P></LI>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0865">AbcdConcept0865</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime/TimeOfDayBegin </TT>
</P></LI>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0866">AbcdConcept0866</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime/ISODateTimeEnd </TT>
</P></LI>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0867">AbcdConcept0867</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime/DayNumberEnd </TT>
</P></LI>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0868">AbcdConcept0868</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime/TimeOfDayEnd </TT>
</P></LI>
<LI>
<P><A href="http://ww3.bgbm.org/abcddocs/AbcdConcept0869">AbcdConcept0869</A>
<TT> /DataSets/DataSet/Units/Unit/Gathering/DateTime/PeriodExplicit </TT></SPAN></P></LI></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=607414522-23022006></SPAN></FONT><FONT face=Arial color=#0000ff
size=2><SPAN class=607414522-23022006>The ABCD fields pretty much cover the
entire concept space. One could argue whether time-zone is relevant to the
description of biological phenomena, but we do know that ship trawls do cross
time-zones (including the date-line), and that daylight savings time could
stretch or compress some nocturnal collecting events if their durations
were calculated too simply.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=607414522-23022006></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=607414522-23022006>To
some extent these arguments are still going on, so analyze your requirements and
your data, then state your position. ;-)</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=607414522-23022006></SPAN></FONT><FONT face=Arial color=#0000ff
size=2><SPAN class=607414522-23022006></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=607414522-23022006>Cheers,</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=607414522-23022006></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=607414522-23022006>-Stan</SPAN></FONT></DIV><!-- Converted from text/plain format -->
<P><FONT size=2>Stanley D. Blum, Ph.D.<BR>Research Information
Manager<BR>California Academy of Sciences<BR>875 Howard St.<BR>San
Francisco, CA<BR>+1 (415) 321-8183<BR><BR></FONT></P>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT
face=Tahoma size=2>-----Original Message-----<BR><B>From:</B> Taxonomic
Databases Working Group List [mailto:TDWG at LISTSERV.NHM.KU.EDU] <B>On Behalf Of
</B>Lynn Kutner<BR><B>Sent:</B> Thursday, February 23, 2006 9:12
AM<BR><B>To:</B> TDWG at LISTSERV.NHM.KU.EDU<BR><B>Subject:</B> Standards for
date / time values?<BR><BR></FONT></DIV><!-- Converted from text/rtf format -->
<P><FONT face=Arial size=2>Hi - </FONT></P>
<P><FONT face=Arial size=2>I'm working with a suite of date attributes that
can include a combination of precise dates, imprecise dates, and ranges of
dates (and the same types of time values). We'd like to follow existing
standards. If this sort of date / time standard exists, I'd appreciate leads
to the appropriate resources.</FONT></P>
<P><FONT face=Arial size=2>Thank you for your help -</FONT> <BR><FONT
face=Arial size=2>Lynn</FONT> </P><BR>
<P><FONT face="Comic Sans MS" size=2>Lynn Kutner</FONT> <BR><I><FONT
face="Comic Sans MS" color=#808080 size=2>Data Management
Coordinator</FONT></I> <BR><I><FONT face="Comic Sans MS" color=#808080
size=2>NatureServe</FONT></I> <BR><FONT face="Comic Sans MS" color=#808080
size=2>Email: lynn_kutner at natureserve.org</FONT> <BR><FONT
face="Comic Sans MS" color=#808080 size=2>Phone: (303)
541-0360</FONT> <BR><A href="file://www.natureserve.org"><U></U><U><FONT
face="Comic Sans MS" color=#0000ff
size=2>www.natureserve.org</FONT></U></A><FONT face="Comic Sans MS" size=2>
</FONT></P></BLOCKQUOTE></BODY></HTML>
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