trunk/branch integration: documentation

Foundation/include/Poco/DateTime.h

@@ -55,6 +55,10 @@ class Foundation_API DateTime
         /// The class is mainly useful for conversions between
         /// UTC, Julian day and Gregorian calendar dates.
         ///
+        /// The date and time stored in a DateTime is always in UTC
+        /// (Coordinated Universal Time) and thus independent of the 
+        /// timezone in effect on the system.
+        ///
         /// Conversion calculations are based on algorithms
         /// collected and described by Peter Baum at
         /// http://vsg.cape.com/~pbaum/date/date0.htm