Within a citation (such as <mixed-citation> or <related-object>), this element names the publication date of the cited source. All other dates within a citation should be tagged as <date-in-citation>.
The following, in order:
Optionally any one of:
The following, in order:
<day> Day (in a citation), zero or one
<month> Month (in a citation), zero or one
<era> Era (in a citation), zero or one