diff --git a/src/wp-includes/query.php b/src/wp-includes/query.php
index e689828c21..255758b352 100644
--- a/src/wp-includes/query.php
+++ b/src/wp-includes/query.php
@@ -323,6 +323,8 @@ function is_date() {
 /**
  * Is the query for an existing day archive?
  *
+ * A conditional check to test whether the page is a date-based archive page displaying posts for the current day.
+ *
  * @since 1.5.0
  *
  * @global WP_Query $wp_query Global WP_Query instance.