After the recent DST time change in USA on November 7th 2010, Scheduled processes are running one hour behind in our case. Our base time zone is EST. This happens due to a bug in the current Tools version less than 8.50.13. This issue is fixed in 8.50.13 and 8.51.
To resolve this issue, restart all your batch server domains in DEV/QA/PROD. Both NT and unix server domains are affected by this issue.
For more detail see : E-PRCS: 8.50 After DST change processes run one hour ahead/behind scheduled time (Doc ID 1265111.1)
References NOTE:1163113.1 - E-PRCS Processes Are in "Queued" Status when Process Scheduler Resides in a Different Time Zone
This happens due to inability of process scheduler to detect change in sessiontimezone after the DST change and it’s use of the following SQL in 8.50
select ..... from PSPRCSQUE........where RUNDTTM <= SYSTIMESTAMP
By understanding the Oracle DBMS concept of SYSTIMESTAMP, the session time zone also takes effect when a TIMESTAMP value is converted to the TIMESTAMP WITH TIME ZONE or TIMESTAMP WITH LOCAL TIME ZONE datatype.
Therefore, for this conversion to take place : RUNDTTM <= SYSTIMESTAMP, the user's session timezone is returned and is not the same timezone as the database server.
Note: This only impacts those customers using Oracle and PT 8.50.12 or less. It does not impact non Oracle or lower tools release customers.