OWL-Time is an OWL-2 DL ontology of temporal concepts, for describing the temporal properties of resources in the world or described in Web pages. The ontology provides a vocabulary for expressing facts about topological (ordering) relations among instants and intervals, together with information about durations, and about temporal position including date-time information. Time positions and durations may be expressed using either the conventional (Gregorian) calendar and clock, or using another temporal reference system such as unix-time, geologic time, or different calendars.
The namespace for OWL-Time terms is http://www.w3.org/2006/time#
The suggested prefix for the OWL-Time namespace is time:
The OWL-Time ontology is available here.
An ontology of individuals for the Gregorian calendar (months) is available here.
General Information
For OGC - This is a Public Draft of a document prepared by the Spatio-temporal Data on the Web Working Group (SDW) — a joint W3C-OGC project (see charter). The document is prepared following W3C conventions. Recipients of this document are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to provide supporting documentation.
New classes and properties are introduced in this revision of OWL-Time. The new elements primarily relate to relaxing the limitation that time position uses only the Gregorian Calendar, and are placed in a ogical hierarchy in relation to the original elements. While there is less implementation evidence for these than the elements from the 2006 version, the new elements are essential to satisfying key requirements in the revision.
However, a small number of other new elements merit additional explanation:
In this vocabulary specification, Manchester syntax [[owl2-manchester-syntax]] is used where the value of a field is not a simple term denoted by a URI or cURI.
RDF representations of OWL-Time are available at the vocabulary namespace URI - see Notation and namespaces.
OWL-Time supports the representation of temporal entities and relations within applications that require these concepts. Implementations that produce, maintain, publish or consume temporal information using OWL-Time must take steps to ensure security and privacy considerations are addressed at the application level.
OWL-Time has been put into use in a large number of applications. Some of these are summarized here.
This version of OWL-Time was developed in the Spatial Data on the Web Working Group (a joint activity involving W3C and the Open Geospatial Consortium). The Ontology is derived from the one described in the 2006 Draft [[owl-time-20060927]] though the document has been completely re-written.
The principal technical changes are as follows:
:xsdDateTime deprecated as used on :DateTimeInterval -
difficult/ambiguous encoding
:Year deprecated
:January deprecated
:TemporalEntity and range
xsd:duration
Results of wide review of OWL-Time is summarized here.
A number of requirements relating to Time were identified in the Spatial Data on the Web Use Cases & Requirements [[sdw-ucr]]. This section provides brief descriptions of how these requirements have been resolved.
prov:Activity could itself be modelled as an
rdfs:subClassOf of :TemporalEntity.
Allen's interval algebra described in Temporal Entitites and Relations can support the description of temporal
relationships between activities in a provenance trace. However, these applications have not been explicitly
modelled in this document.
The editors would like to thank the members of the W3C/OGC Spatial Data on the Web Working Group for their contributions during the development of this document.