If you view source on the page it has an error:
date(): Invalid date.timezone value "Berlin/London', we selected the timezone 'UTC' for now.
This means your php.ini configuration file or code on the page somewhere is setting the timezone to an invalid value. You can probably get that updated in your hosting control panel or talk to your hosting provider to see where to set the default time zone.
Since I have access to your server via FTP I went ahead and added a line to the top of /webassist/globals/globals.php to set the timezone to a correct value. That will prevent the error as well by overriding the incorrect default, but you may still want to get it set correctly on the server as well.