Index: wp-includes/post.php
===================================================================
--- wp-includes/post.php	(revision 44730)
+++ wp-includes/post.php	(working copy)
@@ -1,4 +1,4 @@
-<?php
+<?php
 /**
  * Core Post API
  *
@@ -6249,6 +6249,19 @@
 
 	$timezone = strtolower( $timezone );
 
+	/**
+	 * Filter the post type of which to get the latest modified or published time.
+	 *
+	 * @since 5.x
+	 *
+	 * @param string $post_type Optional. The post type to check. Default 'any'.
+	 * @param string $timezone  The timezone for the timestamp. See get_lastpostdate().
+	 *                          for information on accepted values.
+	 * @param string $field     Post field to check: 'date' or 'modified'.
+	 * @return string
+	 */
+	$post_type = apply_filters( '_get_last_post_time_post_type', $post_type, $timezone, $field );
+
 	$key = "lastpost{$field}:$timezone";
 	if ( 'any' !== $post_type ) {
 		$key .= ':' . sanitize_key( $post_type );