diff --git src/wp-includes/general-template.php src/wp-includes/general-template.php
index cb61c58..b5f2b5b 100644
--- src/wp-includes/general-template.php
+++ src/wp-includes/general-template.php
@@ -1428,15 +1428,15 @@ function the_date( $d = '', $before = '', $after = '', $echo = true ) {
  * @since 3.0.0
  *
  * @param string $d Optional. PHP date format defaults to the date_format option if not specified.
- * @return string|null Null if displaying, string if retrieving.
+ * @return string Date the current $post was written.
  */
 function get_the_date( $d = '' ) {
 	$post = get_post();
 
-	if ( '' == $d )
-		$the_date = mysql2date( get_option( 'date_format' ), $post->post_date );
-	else
-		$the_date = mysql2date( $d, $post->post_date );
+	if ( '' == $d ) {
+		$d = get_option( 'date_format' );
+	}
+	$the_date = mysql2date( $d, $post->post_date );
 
 	return apply_filters( 'get_the_date', $the_date, $d );
 }