Ticket #32835: 32835.patch

src/wp-includes/date.php

@@ -356 +356 @@
                 // Weeks per year.
                 if ( isset( $_year ) ) {
                         // If we have a specific year, use it to calculate number of weeks.
-                        $date = new DateTime();
-                        $date->setISODate( $_year, 53 );
-                        $week_count = $date->format( "W" ) === "53" ? 53 : 52;
+                        $week_count = date('W',mktime(0,0,0,12,28,$date_query['year']));
 
                 } else {
                         // Otherwise set the week-count to a maximum of 53.