GregorianCalendar: I seem to always be five (5) hours head in my value.

Question

The following just outputs the milliseconds of the current datetime in Central Standard Time (CST).
What I am try to test is this line:
calendar.add(Calendar.HOUR_OF_DAY, 0);When I try the following:
package test;
import java.util.Date;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.SimpleTimeZone;
import java.util.TimeZone;
public class GetCal {
     public static void main(String args[]){
          String[] ids = TimeZone.getAvailableIDs(-6 * 60 * 60 * 1000);
          if (ids.length == 0) {
              System.exit(0);
          System.out.println("Current Time");
          SimpleTimeZone pdt = new SimpleTimeZone(-6 * 60 * 60 * 1000, ids[0]);
          // set up rules for daylight savings time
          pdt.setStartRule(Calendar.APRIL, 1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
          pdt.setEndRule(Calendar.OCTOBER, -1, Calendar.SUNDAY, 2 * 60 * 60 * 1000);
          Calendar calendar = new GregorianCalendar(pdt);
          Date trialTime = new Date();
          calendar.setTime(trialTime);
          calendar.add(Calendar.HOUR_OF_DAY, 0);
          long nCalTime = calendar.getTimeInMillis();
          String nCalTimeValue = String.valueOf(nCalTime);
          System.out.println("Long " + nCalTime);
          System.out.println("String " + nCalTimeValue);
}I would output something similar to:
1149624386040
I would take this value and run it in the following SQL to verify the datetime:
VARIABLE millis NUMBER
EXEC :millis := 1149624386040;
ALTER SESSION SET NLS_DATE_FORMAT = 'DD-MON-YYYY HH:MI:SS AM';
SELECT TO_DATE('197001','YYYYMM') + (:millis / 1000 / 60 / 60 / 24) converted
FROM DUAL;The result would be:
06-JUN-2006 08:06:26 PM
However, the actual time would be:
06-JUN-2006 03:06:26 PM
Thus, I am five hours ahead.
Since I am adding zero (0) in:
calendar.add(Calendar.HOUR_OF_DAY, 0);I thought I should get the correct time, however I always seem to be five hours ahead.
I'd greatly appreciate any help or corrects.
Thank you,
--Todd                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               

Answer 1

DrClap: I greatly appreciate your help with this.
I ran the following:
select DBTIMEZONE from dual;This returned "-06:00".
In a nutshell, I am testing with the current date - but what I have is a JSF MyFaces Calendar component that represents a date and a JSF listbox with the values 0 - 23 as hours options.
A user will pick a date and select an hour.
I have converted the date to milliseconds, add the selected hour and the resulting value needs to be in milliseconds.
This value will be passed to a method that will return a list of transactions for the user's picked date and selected hour. I have no control of the method - I am only consuming.
I am testing with the current date, to make sure everything is converting to milliseconds correctly - which it's not since I seem to be five (5) hours ahead.
Now that I know that the Oracle database server as a DBTIMEZONE value of "-06:00"; do I just create a static variable of (5 hours) 18000000 and just subtract that from the millisecond value that is made up of the picked date and selected hour?
There has to be a better way?
Thanks,
--Todd