cache sitemap for 1 day

Author: dannyvankooten

includes/set-cache-headers.php

@@ -19,7 +19,10 @@
     } elseif (is_404()) {
         $headers['Cache-Control'] = 'public, max-age=3600';
 
-    // cache all other pages for 30 days
+    // cache feeds and XML files (ie sitemap) for 1 day
+    } elseif (is_feed() || str_ends_with($_SERVER['REQUEST_URI'] ?? '', '.xml')) {
+        $headers['Cache-Control'] = 'public, max-age=81600';
+    // cache all other pages for 1 year
     } else {
         $headers['Cache-Control'] = 'public, max-age=2592000';
     }