wp-includes/class-wp-rewrite.php:495Retrieves date permalink structure, with year, month, and day.
string|false public function get_date_permastruct() { if ( isset( $this->date_structure ) ) { return $this->date_structure; } if ( empty( $this->permalink_structure ) ) { $this->date_structure = ''; return false; } // The date permalink must have year, month, and day separated by slashes. $endians = array( '%year%/%monthnum%/%day%', '%day%/%monthnum%/%year%', '%monthnum%/%day%/%year%' ); $this->date_structure = ''; $date_endian = ''; foreach ( $endians as $endian ) { if ( str_contains( $this->permalink_structure, $endian ) ) { $date_endian = $endian; break; } } if ( empty( $date_endian ) ) { $date_endian = '%year%/%monthnum%/%day%'; } /* * Do not allow the date tags and %post_id% to overlap in the permalink * structure. If they do, move the date tags to $front/date/. */ $front = $this->front; preg_match_all( '/%.+?%/', $this->permalink_structure, $tokens ); $tok_index = 1; foreach ( (array) $tokens[0] as $token ) { if ( '%post_id%' === $token && ( $tok_index <= 3 ) ) { $front = $front . 'date/'; break; } ++$tok_index; } $this->date_structure = $front . $date_endian; return $this->date_structure; }Introduced in 1.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/class-wp-rewrite.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.