Default Stats Jobs

Show current Global defaults for object stats gathering
These can be set with the DBMS_STATS.SET_GLOBAL_PREFS procedure.

SELECT sname as Name,
       SVAL1 || SPARE4 AS Value
  FROM sys.optstat_hist_control$
 ORDER BY 1;

View info About Nightly Stats Collection Jobs (10g)

SELECT JOB_NAME, 
       SCHEDULE_NAME, 
       JOB_CLASS, 
       RUN_COUNT, 
       LAST_START_DATE, 
       LAST_RUN_DURATION, 
       NEXT_RUN_DATE 
  FROM DBA_SCHEDULER_JOBS 
 WHERE JOB_NAME = 'GATHER_STATS_JOB';

View info About Nightly Stats Collection Jobs (11g)

select window_name, job_start_time, job_duration
   from dba_autotask_job_history
  where client_name = 'auto optimizer stats collection'
  order by job_start_time desc;