Representing Knowledge in Semantic Cultural Web

Information must be put in the right spatial and temporal context
Dates are often indetermined
- beginning 1800
- mid 19^th century
- between 1712 and 1715
- circa 1827
- ...
We have to manage both simple and interval dates
We need a temporal algebra to support operators like:
- <Date1> is before <Date2>
- <Date1> partially overlaps <Date2>
- <Date1> in <Date2>
and chronologically ordering
Ordering etherogeneous dates is a non trivial semantic issue
Are the following dates in chronological order?
- 1^st January 1800
- probably 2 February 1800 (anyway between January and April 1800)
- beginning year 1800
- mid year 1800
- first half of 19^th century
- probably in 1810 (certainly after end of year 1800 and before end year 1832)
- 19^th century

Temporal algebra