ISSUE-163: Which time? Leap seconds?
Which time? Leap seconds?
- State:
- CLOSED
- Product:
- Time ontology in OWL
- Raised by:
- Simon Cox
- Opened on:
- 2017-04-12
- Description:
- From https://www.w3.org/XML/2007/qts-timeont-comments#id63903
Which system of time is used in dateTime descriptions? UTC, UT1, UT0, mean solar time, actual solar time, international atomic time, ephemerides time, ... ?
Does it vary between descriptions? If so, where does a description inform the user which system of time is in use? If not, where does the ontology tell the user which system is to be used to interpret dateTime descriptions?
If UTC is intended, then what policy is adopted by the ontology regarding leap seconds? Are they included? excluded? If included, then how can valid descriptions for times in the future be distinguished from meaningless constructs which denote no point or interval in time?
The XML Schema specification answers these questions for the dateTime type, but nothing in the ontology says explicitly that those answers apply to dateTime descriptions. - Related Actions Items:
- No related actions
- Related emails:
- RE: OWL-Time - ISSUE-163: Which time? Leap seconds? (from chris.little@metoffice.gov.uk on 2017-04-13)
- OWL-Time - ISSUE-163: Which time? Leap seconds? (from Simon.Cox@csiro.au on 2017-04-12)
Related notes:
Proposed disposition from email 2017-04-13
The default temporal reference system is Gregorian UTC. This includes leap seconds as specified by the IERS. The ISO8601 standard states this explicitly. See Section 3.3.
If one wishes to use another timescale, such as a pseudo-Gregorian without leap seconds, or UT0, or TAI, etc., one uses the time:TRS class and the time:hasTRS property to specify the Temporal Reference System. Example 5.2 demonstrates this for the Hebrew calendar.
Producing a definitive list of calendars and timescales is out of scope of this work, but is obviously desirable.
Display change log
