diff --git a/wp-includes/class-wp-locale.php b/wp-includes/class-wp-locale.php
index 2c42e3a8c7..0f97518baa 100644
--- a/wp-includes/class-wp-locale.php
+++ b/wp-includes/class-wp-locale.php
@@ -271,8 +271,8 @@ class WP_Locale {
 	 *
 	 * @since 2.1.0
 	 *
-	 * @param string $weekday_name
-	 * @return string
+	 * @param string $weekday_name Full translated weekday word
+	 * @return string Translated weekday initial
 	 */
 	public function get_weekday_initial( $weekday_name ) {
 		return $this->weekday_initial[ $weekday_name ];