diff --git a/wp-includes/post.php b/wp-includes/post.php
index 6a0af16a8b..ad271c2ab8 100644
--- a/wp-includes/post.php
+++ b/wp-includes/post.php
@@ -4945,9 +4945,9 @@ function wp_resolve_post_date( $post_date = '', $post_date_gmt = '' ) {
 	}
 
 	// Validate the date.
-	$month = substr( $post_date, 5, 2 );
-	$day   = substr( $post_date, 8, 2 );
-	$year  = substr( $post_date, 0, 4 );
+	$month = (int) substr( $post_date, 5, 2 );
+	$day   = (int) substr( $post_date, 8, 2 );
+	$year  = (int) substr( $post_date, 0, 4 );
 
 	$valid_date = wp_checkdate( $month, $day, $year, $post_date );
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 4fde759d36..8484b73a06 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.1-alpha-54125';
+$wp_version = '6.1-alpha-54126';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.