Retrieves date permalink structure, with year, month, and day.
The permalink structure for the date, if not set already depends on the permalink structure. It can be one of three formats. The first is year, month, day; the second is day, month, year; and the last format is month, day, year. These are matched against the permalink structure for which one is used. If none matches, then the default will be used, which is year, month, day.
Prevents post ID and date permalinks from overlapping. In the case of post_id, the date permalink will be prepended with front permalink with ‘date/’ before the actual permalink to form the complete date permalink structure.
(string|false) Date permalink structure on success, false on failure.