oracle 日期 段查询

select so.fullname,su.username,t.* from zh_process t,sysorgan so,sysuser su
where t.isvalid = '1' and t.responsible_deptid = so.oid and t.bzld = su.oid and
t.RESPONSIBLE_DEPTID like'%3%'
and  to_date( t.create_time,'yyyy-MM-dd' ) > to_date('2007-10-09', 'yyyy-MM-dd')
and  to_date( t.create_time,'yyyy-MM-dd' )  < to_date('2009-10-16', 'yyyy-MM-dd')
  order by t.oid desc