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Temporal extent

Name Temporal extent
Definition Time period covered by the content of the resource
Obligation
  • dataset or dataset series: conditional
  • service: conditional
Multiplicity [0..*] for a temporal extent but at least one reference date must be documented.
Example Start date: 2002-03-10T15:11:28
End date: 2011-01-15T09:10:00
Start date: unknown
End date: 2008-12-31T09:10:00
Start date: 2012-06-12T11:45:30
End date: now
Temporal extent primarily refers to the data collection period. However, if a data resource refers to a historical period, such as the geological Cretaceous period, then temporal extent refers to the moment when data were found or collected. Temporal extent is defined by the start and end dates of data, or either of these. If the start date is not known, it is dropped and only the end date is used. If data are still added to a resource, the end date is dropped, while the start date is indicated, which is also reflected in data status, as being updated.

Tehnical data
 
INSPIRE equivalent Temporal extent
Comparison with INSPIRE equivalent
ISOequivalent [351] extent
Comparison with ISO equivalent
XPath identificationInfo[1]/*/extent/*/temporalElement/*/extent
Data type TM_primitive
Domain TM_primitive<<CodeList>> [ISO 19108]
Implementation instructions Temporal extent may be defined in the following forms:
  • individual dates
  • interval of dates expressed using the initial and final date of the time interval
  • combination of individual dates and intervals of dates.
The value of one of the start or end dates may be unknown (start date not defined or known) or have a value now (not ended and still valid).


Encoding example 1: Date interval - known start and end dates
 
<gmd:MD_Metadata...
...
     <gmd:identificationInfo>
         <gmd:MD_DataIdentification>
...
             <gmd:extent>
                 <gmd:EX_Extent>
                     <gmd:temporalElement>
                         <gmd:EX_TemporalExtent>
                             <gmd:extent>
                                 <gml:TimePeriod gml:id="IDd2febbb4-e66f-4ac8-ba76-8fd9bc7c8be6">
                                     <gml:beginPosition>2002-03-10T15:11:28</gml:beginPosition>
                                     <gml:endPosition>2011-01-15T09:10:00</gml:endPosition>
                                 </gml:TimePeriod>
                             </gmd:extent>
                         </gmd:EX_TemporalExtent>
                     </gmd:temporalElement>
                 </gmd:EX_Extent>
             </gmd:extent>
...
         </gmd:MD_DataIdentification>
...
     </gmd:identificationInfo>
...
</gmd:MD_Metadata>

Encoding example 2: Date interval - unknown start, known end date
 
<gmd:MD_Metadata...
...
     <gmd:identificationInfo>
         <gmd:MD_DataIdentification>
...
             <gmd:extent>
                 <gmd:EX_Extent>
                     <gmd:temporalElement>
                         <gmd:EX_TemporalExtent>
                             <gmd:extent>
                                 <gml:TimePeriod gml:id="ID45b09f50-23ec-11ea-978f-2e728ce88125">
                                     <gml:beginPosition indeterminatePosition="unknown"/>
                                     <gml:endPosition>2008-12-31T09:10:00</gml:endPosition>
                                 </gml:TimePeriod>
                             </gmd:extent>
                         </gmd:EX_TemporalExtent>
                     </gmd:temporalElement>
                 </gmd:EX_Extent>
             </gmd:extent>
...
         </gmd:MD_DataIdentification>
...
     </gmd:identificationInfo>
...
</gmd:MD_Metadata>

Encoding example 3: Date interval - known start date, not over, and still valid
 
<gmd:MD_Metadata...
...
     <gmd:identificationInfo>
         <gmd:MD_DataIdentification>
...
             <gmd:extent>
                 <gmd:EX_Extent>
                     <gmd:temporalElement>
                         <gmd:EX_TemporalExtent>
                             <gmd:extent>
                                 <gml:TimePeriod gml:id="ID53e78aae-23f9-11ea-978f-2e728ce88125">
                                     <gml:beginPosition>2012-06-12T11:45:30</gml:beginPosition>
                                     <gml:endPosition indeterminatePosition="now"/>
                                 </gml:TimePeriod>
                             </gmd:extent>
                         </gmd:EX_TemporalExtent>
                     </gmd:temporalElement>
                 </gmd:EX_Extent>
             </gmd:extent>
...
         </gmd:MD_DataIdentification>
...
     </gmd:identificationInfo>