问题
Can ISO 8601 represent a date such as "Summer 2011"?
The closest I can think of is "2011-07" or fallback to "2011". Of course if you are allowed to make use of time intervals you could use "2011-06-01/2011-08-31", but I am interested in possibilities that can be used in Wikidata and I don't thing the time interval solution can be used there.
来源：https://stackoverflow.com/questions/42468714/can-iso-8601-represent-a-date-such-as-summer-2011