oracle job "next run date"

Question

My oracle database time zone is +03:30 (TEHRAN)

select current_timestamp from dual

22-JAN-24 11.06.09.128998 AM +03:30


 dbms_scheduler.create_job (
              job_name          => v_job_name ,
              job_type          => 'PLSQL_BLOCK',
              job_class         => 'DEFAULT_JOB_CLASS',
              job_action        => v_stmt,
              start_date        => SYSDATE,
              enabled           => TRUE,
              auto_drop         => TRUE
              );

but when we set a job to be runned immediately in my current sysdate ,My job run after 3.5 hours !

but we expect that my job run immediatly;

Answer 1

"My oracle database time zone is +03:30 (TEHRAN)" - What does it mean?

See How to handle Day Light Saving in Oracle database

current_timestamp returns the current time in your SESSIONTIMEZONE, however SYSDATE returns the current time in the time zone of database server's operating system.

Parameter start_date has data type TIMESTAMP WITH TIME ZONE, your input value is converted implicitly as

FROM_TZ(CAST(SYSDATE AS TIMESTAMP), SESSIONTIMEZONE)

However, in principle you would require

FROM_TZ(CAST(SYSDATE AS TIMESTAMP), TO_CHAR(SYSTIMESTAMP, 'tzr'))

Try

dbms_scheduler.create_job (
          job_name          => v_job_name ,
          job_type          => 'PLSQL_BLOCK',
          job_class         => 'DEFAULT_JOB_CLASS',
          job_action        => v_stmt,
          start_date        => CURRENT_TIMESTAMP,
          enabled           => TRUE,
          auto_drop         => TRUE
          );

or

dbms_scheduler.create_job (
          job_name          => v_job_name ,
          job_type          => 'PLSQL_BLOCK',
          job_class         => 'DEFAULT_JOB_CLASS',
          job_action        => v_stmt,
          start_date        => SYSTIMESTAMP,
          enabled           => TRUE,
          auto_drop         => TRUE
          );

Either of them should work.

Answer 2

SELECT FROM_TZ(CAST(TO_DATE('22-JAN-24 11.06.09.128998', 

      'YYYY-MM-DD HH:MI:SS:FFF') AS TIMESTAMP), 'Iran/Tehran') 
   AT TIME ZONE 'Iran/Tehran' "Tehran Time" 
   FROM DUAL;

Tehran Time