Backport fix to solve warning problems.

htdocs/core/class/conf.class.php

@@ -201,6 +201,11 @@ class Conf
 		//var_dump($this->modules);
 		//var_dump($this->modules_parts['theme']);
 
+		// If you can't set timezone of your PHP, set this constant. Better is to set it to UTC.
+		// In future, this constant will be forced to 'UTC' so PHP server timezone will not have effect anymore.
+		//$this->global->MAIN_SERVER_TZ='Europe/Paris';
+		if (! empty($this->global->MAIN_SERVER_TZ) && $this->global->MAIN_SERVER_TZ != 'auto') date_default_timezone_set($this->global->MAIN_SERVER_TZ);
+
 		// Object $mc
 		if (! defined('NOREQUIREMC') && ! empty($this->multicompany->enabled))
 		{