OWL Time Ontology adoption

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The tables below list a number of ontologies and datasets that utilize elements from OWL-Time. The list is not exhaustive.

Original OWL-Time features

The original version of OWL-Time was published as a W3C Note in 2006, and has been recognised as the primary basic time ontology by many parts of the community. However, universal adoption of OWL-Time, alongside core vocabularies and ontologies like FOAF, Dublin Core, OWL, PROV-O, SKOS and the W3C Organization Ontology, has been compromised by its uncertain status. Though there are many examples of adoption of OWL-Time, their temporal distribution is uneven, and may have diminished as the community became aware of the actual status of the 2006 note, though there was no challenge to the quality of the ontology. The current (2017) revision and standards-track activity is intended to be a long-overdue correction to this situation.

New features

The original version of OWL-Time limited the description of time position to use of the Gregorian calendar and 24 hour clock. This prevented adoption of OWL-Time in geology, archeology, cosmology, and in applications designed for other cultures. New features in this revision remove the restriction, by adding super-classes and siblings to the original features, while respecting and preserving all the original features. While the extensions were triggered by well documented needs, the specific implementation only has a few implementations. Nevertheless, the value of the new features appears to have been demonstrated.

Transition criteria

The W3C criteria for exiting 'Candidate Recommendation' status are based on

(a) number of implementations of each element of the ontology

(b) the expectation that these will include both producing and consuming applications.

For a low-level ontology like OWL-Time, the appearance of elements from the ontology are likely to be a minor feature of a specific application. Nevertheless, we can broadly distinguish between

  1. ontologies which use OWL-Time classes or properties as the basis for more specific application classes or properties through sub-classing, or which use OWL-Time classes as the domain or range of property definitions, or in constraints in class definitions, and
  2. data which mentions OWL-Time classes and properties in 'marked-up' datasets.

These two cases are related to the 'producing' and 'consuming' types mentioned by W3C. For that reason, in the tables below we indicate the general division between 'ontologies' and data by rendering the latter in bold.

Some OWL-Time implementations

Number source type OWL-Time classes or properties mentioned
T1 From LOV - Vocabulary re-use http://lov.okfn.org/dataset/lov/vocabs/time Ontologies Tabulation of ontologies known to LOV that use time: https://goo.gl/8oFbNy ; tabulation of OWL-Time classes referred to directly https://goo.gl/4kF1Po
T2 http://purl.org/NET/c4dm/timeline.owl Ontology  :Instant :Interval :hasBeginning :hasEnd
T3 http://ontology.fiesta-iot.eu/ontologyDocs/fiesta-iot.owl Ontology  :Instant :inXSDDateTime
T4 http://data.archiveshub.ac.uk data  :intervalsStarts :intervalEnds :intervalContains :intervalDuring
T5 http://reference.data.gov.uk/def/central-government Ontology  :Instant :DurationDescription
T6 http://rdfs.co/bevon/ Ontology, data  :DurationDescription :hasDurationDescription :years
T7 http://purl.org/ontology/cco/core# Ontology, data  :Interval :inXSDDateTime
T8 http://purl.org/ontology/wi/core# Ontology, data  :Interval :TemporalEntity
T9 http://purl.org/vocab/bio/0.1/ Ontology  :ProperInterval
T10 http://lod.taxonconcept.org/ontology/txn.owl Ontology  :DateTimeDescription :before :after :year
T11 http://reference.data.gov.uk/def/intervals/ Ontologies  :DateTimeInterval :DayOfWeek :DurationDescription :Instant :Interval :MonthOfYear :dayOfWeek :monthOfYear :seconds :months :hours :days :minutes :years :hasDurationDescription :hasBeginning :intervalContains :Thursday :Friday :Monday :Wednesday :Tuesday :Saturday :Sunday
T12 http://reference.data.gov.uk/id/quarter/2006-Q1 etc data  :Instant :Interval :inXSDDateTime :hasBeginning :hasDurationDescription :hasEnd :intervalMetBy :intervalDuring :intervalMeets :intervalEquals :intervalContains :DayOfWeek :Thursday :Friday :Monday :Wednesday :Tuesday :Saturday :Sunday
T13 http://perio.do/technical-overview/#temporal-extent http://n2t.net/ark:/99152/p0v Ontology  :DateTimeDescription :ProperInterval :year :hasDateTimeDescription :intervalStartedBy :intervalFinishedBy
T14 http://sweet.jpl.nasa.gov/2.3/propTime.owl http://sweet.jpl.nasa.gov/2.3/relaTime.owl http://sweet.jpl.nasa.gov/2.3/reprTime.owl http://sweet.jpl.nasa.gov/2.3/reprTimeDay.owl http://sweet.jpl.nasa.gov/2.3/reprTimeSeason.owl NOTE:SWEET ontologies have a large number of classes, representing information that would be 'data' in other RDF styles Ontologies, data  :TemporalEntity :Instant :Interval :ProperInterval :before :after :hasBeginning :hasEnd
T15 http://sweet.jpl.nasa.gov/2.3/stateTimeGeologic.owl Ontology, data  :Instant (with SWEET properties to overcome Gregorian time issue!)
T16 http://bioportal.bioontology.org/search: http://bioportal.bioontology.org/ontologies/PEAO http://purl.bioontology.org/ontology/PROCCHEMICAL http://bioportal.bioontology.org/ontologies/PP http://bioportal.bioontology.org/ontologies/MINERAL http://bioportal.bioontology.org/ontologies/MATRCOMPOUND http://bioportal.bioontology.org/ontologies/MATRELEMENT http://bioportal.bioontology.org/ontologies/MATRROCK http://bioportal.bioontology.org/ontologies/RCTONT http://bioportal.bioontology.org/ontologies/MOC NOTE:BioPortal/obo ontologies have a large number of classes, representing information that would be 'data' in other RDF styles ontologies, data  :TemporalEntity :Instant :Interval :ProperInterval :DateTimeInterval :DurationDescription :DateTimeDescription :TemporalUnit :DayOfWeek :hasEnd :hasBeginning
T17 http://linkedevents.org/ontology/ Ontology  :TemporalEntity :DateTimeInterval :atTime == :hasTime
T18 http://purl.org/ontology/storyline BBC Storyline Ontology Ontology  :TemporalEntity
T19 http://purl.org/ontology/mo/ https://github.com/motools/musicontology Music Ontology Ontology  :TemporalEntity
T20 http://rdf.muninn-project.org/ontologies/military Ontology  :TemporalEntity
T21 https://w3id.org/seas/EvaluationOntology Smart Energy Aware Evaluation ontology, in particular https://w3id.org/seas/TimeOntology Ontology  :TemporalEntity :Instant :ProperInterval :hasBeginning :hasEnd :inXSDDateTime
T22 http://ontology.eil.utoronto.ca/GCI/Foundation/GCI-Foundation.owl http://lov.okfn.org/dataset/lov/vocabs/gci Ontologies  :Interval :DateTimeDescription :hasDateTimeDescription
T23 http://resource.geosciml.org/ontology/timescale/thors/w3c Ontology  :ProperInterval :Instant :TimePosition :Duration :hasMember :hasBeginning :hasEnd :intervalIn :intervalContains :intervalFinishedBy :intervalMetBy :intervalStartedBy
T24 http://resource.geosciml.org/ontology/timescale/gts/w3c Ontology  :intervalIn :intervalStarts :intervalContains :intervalFinishedBy :intervalStartedBy :intervalFinishes :TemporalPosition :TemporalDuration
T25 http://doi.org/10.4225/08/5914ef9e2c6b5 (also http://resource.geosciml.org/classifier/ics/ischart/) data  :Duration :Instant :ProperInterval :TimePosition :TRS
intervalContains :intervalDuring :intervalFinishedBy :intervalFinishes :intervalIn
intervalMeets :intervalMetBy :intervalStartedBy :intervalStarts
hasBeginning :hasEnd :hasTRS :inTemporalPosition :numericDuration :numericPosition :unitType
T26 RSCtx http://softeng.polito.it/rsctx/ https://fedcsis.org/proceedings/2016/pliks/428.pdf Ontology  :DayOfWeek :Instant :ProperInterval :Sunday :Saturday :Monday :Tuesday :Wednesday :Thursday :Friday
T27 SNaP Stuff http://data.press.net/ontology/stuff/ Ontology  :Instant
T28 The Event Ontology http://motools.sourceforge.net/event/event.html Ontology  :TemporalEntity
T29 Semantic Sensor Network Ontology https://www.w3.org/TR/vocab-ssn/ Ontologies  :TemporalEntity :Instant :Interval :inXSDDateTimeStamp :hasBeginning :hasEnd
T30 ALIADA http://aliada-project.eu/2014/aliada-ontology Ontology  :month :ProperInterval
T31 Federated Infrastructures https://github.com/w3c/omn Ontology and example data  :Instant :Interval :hasEnd :hasBeginning :inXSDDateTime
T32 TNO Ontologies http://ontology.tno.nl/ in particular SAREF, Logistics and Transport ontologies Ontologies  :TemporalUnit :Instant :Interval :inXSDDateTime :hasBeginning :hasEnd
T33 Geoscience Australia surveys linked data http://pid.geoscience.gov.au/surveys/ e.g. http://pid.geoscience.gov.au/surveys/survey/01020019?_view=sosa&_format=text%2Fturtle data  :Instant :ProperInterval :hasTime :hasBeginning :hasEnd :inXSDDateTime

Usage of OWL-Time features

Element Usage Comment
 :TemporalEntity T8 T14 T16 T17 T18 T19 T20 T21 T27 T28 T29
 :before :after T10 T14
 :hasBeginning :hasEnd T2 T11 T12 T14 T21 T23 T25 T29 T32 T33
 :hasXSDDuration allows use of xsd:duration to describe the extent of a :TemporalEntity (compare with :inXSDDateTime) (see #f1)
 :hasTime T33 General time predicate. Requested by SDWWG use-cases and modelled after :atTime property found in T17
 :Instant T2 T3 T5 T11 T12 T14 T15 T16 T21 T25 T26 T27 T29 T31 T32 T33
 :inXSDDateTime :inXSDDateTimeStamp T3 T7 T12 T21 T29 T32 T33 allows the use of xsd:DateTime[Stamp] to describe the position of an :Instant
 :Interval T2 T7 T8 T11 T12 T14 T16 T21 T22 T29 T31 T32
 :ProperInterval T9 T13 T14 T16 T21 T23 T25 T26 T30 T33
 :DateTimeInterval T11 T16 T17
 :intervalContains :intervalDuring :intervalEquals :intervalMeets :intervalMetBy T4 T11 T12 T23 T24 T25
 :intervalFinishedBy :intervalFinishes :intervalIn :intervalStartedBy :intervalStarts T4 T13 T23 T24 T25
 :TemporalDuration T24 Generalized class appearing as the range of predicates in OWL-Time. (Transitive) Superclass of :DurationDescription. This usually does not appear directly in data: one of the disjoint sub-classes appears instead.
 :Duration T23 T25
 :GeneralDurationDescription Generalized class appearing as the range of predicates in OWL-Time. Superclass of :DurationDescription. This usually does not appear directly in data: one of the disjoint sub-classes appears instead.
 :DurationDescription T5 T6 T11 T12 T16
 :hasDurationDescription T6 T11 T12
 :seconds :minutes :hours :days :weeks :months :years T6 T11 required by any use of class :DurationDescription
 :TemporalUnit : T16 T25 T32
 :unitType T25 predicate to link to :TemporalUnit
 :TemporalPosition T24 Generalized class appearing as the range of predicates in OWL-Time. (Transitive) Superclass of :DateTimeDescription. This usually does not appear directly in data: one of the disjoint sub-classes appears instead.
 :TimePosition T23 T25
 :inTemporalPosition :numericDuration :numericPosition :nominalPosition T25 New properties to support numeric (timeline) time positions, and named time positions
 :GeneralDateTimeDescription Generalized class appearing as the range of predicates in OWL-Time. Superclass of :DateTimeDescription. This usually does not appear directly in data: one of the disjoint sub-classes appears instead. (see #f1)
 :DateTimeDescription T10 T13 T16 T22
 :hasDateTimeDescription T13 T22
 :second :minute :hour :day :week :month :year T10 T13 T30 required by any use of class DateTimeDescription
 :DayOfWeek T11 T12 T16 T26
 :MonthOfYear T11 Introduced in parallel with DayOfWeek
 :dayOfWeek :monthOfYear T11 standard predicates to link to :DayOfWeek and :MonthOfYear
 :TRS T25 Introduced to support use of OWL-Time for applications beyond those that use the Gregorian calendar/24-hour clock.
 :hasTRS T25 standard predicate to link to :TRS. Note: this is used in OWL-Time ontology itself to fix the value of the TRS to the Gregorian Calendar for the original classes :DateTimeDescription and :DurationDescription for backward compatibility
 :hasMember T23 Used to construct a complex of :ProperIntervals

Additional testimonials

f1: From Rob Warren warren@muninn-project.org on Rationale for keeping unused elements of Time OWL:

Currently, two items within the Time Ontology remain unused by the known implementations: hasXSDDuration and GeneralDateTimeDescription and are "at risk" features:

hasXSDDuration is defined as the "Extent of a temporal entity, expressed using xsd:duration". Since the early web had this resource to document durations, it stands that the feature is needed to reference legacy data.

Furthermore, the exemplar in section in "5.8 Legal interval" makes use of it and the interval ontology has a similar property "hasXsdDurationDescription" which is poorly defined but seems to be the related property. I think this is sufficient evidence that there is a use for this property for legacy linkages to XML.

GeneralDateTimeDescription is needed for a generalization for other calendars as well as a structural ontological "tie-together" for other time units such as Section 5.8's financial quarter "ex: hasFinancialQuarter". I know that ontologists are not too keen on leaf nodes within ontologies, but these are needed for integrations to other views of time across ontologies and datasets. I'm think here of other time-descriptions or units that aren't necessarily formalized, such as school periods, ships's bells or rugby time periods.

In short, my view is that both these properties have yet to be seen in action but are needed to support time structures that have not been previously well supported by computing systems. This may be the reason itself for the lack of use but if we expect ontologies to tackle some of the harder "human time" problems, the hooks need to be in place.

All my best,

rhw