diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index e39a9b6f43..791a2f2712 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Switched to_xml to use the xml schema format for datetimes.  This allows the encoding of time zones and should improve operability. [Koz]
+
 * Added a note to the documentation for the Date related Numeric extensions to indicate that they're
 approximations and shouldn't be used for critical calculations. [Koz]
 
diff --git a/activesupport/lib/active_support/core_ext/hash/conversions.rb b/activesupport/lib/active_support/core_ext/hash/conversions.rb
index 840421789b..4cd171a6d1 100644
--- a/activesupport/lib/active_support/core_ext/hash/conversions.rb
+++ b/activesupport/lib/active_support/core_ext/hash/conversions.rb
@@ -12,7 +12,7 @@ module Conversions
         
         XML_FORMATTING = {
           "date"     => Proc.new { |date| date.to_s(:db) },
-          "datetime" => Proc.new { |time| time.to_s(:db) }
+          "datetime" => Proc.new { |time| time.xmlschema }
         }
         
         def to_xml(options = {})