The Oracle BPEL date function xp20:current-dateTime() comes in very handy whenever we require to track/print the current system timestamp inside a BPEL process at runtime. However, there is a glitch with this function during the daylight savings timezone settings, as this function returns the timestamp 1 hr ahead of the actual time during the daylight savings. This issue was logged with Oracle and the issue was attributed to the JDK version (1.5.0_06) bundled with the SOA suite 10.1.3.3. To resolve this issue at hand, an upgrade to at least JDK version 1.5.0_16 is recommended.
However, to overcome this issue even more easily, you can use the Oracle BPEL XPath extension function ora:getCurrentDateTime() to get the current system timestamp exactly even during daylight saving settings. If you have the same issue, try this out and this should work as it worked fine for me ;)