CREATE TABLE REGISTRATION
(
  EARLY_REGISTRATION_START_DATE  DATE,
  EARLY_REGISTRATION_END_DATE    DATE,
  EARLY_REGISTRATION_START_TIME  DATE,
  EARLY_REGISTRATION_END_TIME    DATE
)

Insert into REGISTRATION
   (EARLY_REGISTRATION_START_DATE, EARLY_REGISTRATION_END_DATE, EARLY_REGISTRATION_START_TIME, 
EARLY_REGISTRATION_END_TIME)
 Values
   (TO_DATE('11/26/2012 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 
TO_DATE('12/03/2012 00:00:00', 'MM/DD/YYYY HH24:MI:SS'), 
TO_DATE('01/01/1900 08:00:00', 'MM/DD/YYYY HH24:MI:SS'), 
TO_DATE('01/01/1900 21:00:00', 'MM/DD/YYYY HH24:MI:SS'));
COMMIT;

select case
         when (trunc(sysdate)                       between 
               trunc(early_registration_start_date) and 
               trunc(early_registration_end_date))
           then
             'Yes'
           else
             'No'
       end show_early_registration
  from registration

select case
         when (trunc(sysdate)                                     between 
               trunc(early_registration_start_date)               and 
               trunc(early_registration_end_date))                and
              (to_char(sysdate, 'hh:mi AM')                       between
               to_char(early_registration_start_time, 'hh:mi AM') and
               to_char(early_registration_end_time, 'hh:mi AM'))
           then
             'Yes'
           else
             'No'
       end show_early_registration
  from registration