1.
Simon Cox
16 September 2015
LAND AND WATER
OWL-Time and enhancements
Briefing for Spatial Data on the Web Working Group

2.
OWL-Time and enhancements | Cox2 |

3.
Allen’s temporal model
OWL-Time and enhancements | Cox3 |

4.
OWL-Time and enhancements | Cox4 |
“2015-03-10T17:10:00.00+01:00”^^xsd:DateTime
gYear, gMonth, gDay tied to Gregorian Calendar
No way to use (or even indicate) other temporal reference systems
e.g. geologic time, GPS/Unix time, Hebrew calendar, archeological periods, dynastic systems …

5.
Generalization to enable other time systems
OWL-Time and enhancements | Cox5 |
No change to existing rdf instances!

6.
Summary
• OWL-Time is based on rigorous temporal calculus, supporting
ordering of events
• All of Allen’s temporal relations are supported for ‘ProperIntervals’
• Time position in OWL-Time is limited to Gregorian calendar
would drive technical and cultural users elsewhere 
• Proposed generalization supports
• Indication of a temporal reference system (externally described)
• more representations:
Coordinate (number on timeline), ordinal values (named intervals)
• Interval logic is retained, no change for existing OWL-Time users
OWL-Time and enhancements | Cox6 |