[type of data: composed data—controlled terms (typed literal); not repeatable]
Optionally record the date when the work was originally released, distributed, published, unveiled, and/or performed, if known. If the work is an ongoing work, not yet completed, use an open date, consisting of the date and a hyphen. If the work was unveiled, released, distributed or published over a span of time, use a range of dates. If the date is unknown but an approximate date can be supplied, do so.
For broadcast works, record a structured date (YYYYMMDD) for the broadcast date.
For naturally occurring objects, record the date the object was found.