On 25 November 2010 14:54, Jakob Voss <[log in to unmask]>
Q: "When did this band play in your town?"
A: "They gave a concert at 2nd and 3rd June"
Q: "Oh, they started playing at 2nd and finished at 3rd?"
A: "No, they gave two shows, one at 2nd, one at 3rd."
Q: "But which date did they play?"
A: "At 2nd, and 3rd, as I said."
Q: "But '2nd and 3rd' is not a date!"
And we aren't (I suggest) trying to represent "the" date of complex constructs like this. The reality is just as you say: there is a set of concerts, and each concert had a date (and a time interval within that date). Surely that is enough for any knowledge representation system.
Does anyone really want to represent dates of this kind of complex construct? If so, why on earth? If we can get a simpler specification by leaving out a doubtful edge case, I would suggest it was very much worth leaving it out.