Notice : The government of Chile recently decided to extend 2011 Daylight Saving Time again. This impacts the (UTC -4:00) Santiago timezone
Instead of ending the first Saturday in April, DST will now end the first Saturday in May. There is no hotfix for this change.
For more information, see the regional blog : http://blogs.technet.com/b/latam/archive/2011/03/29/updated-chile-dst-changes-2011.aspx