Select between dates in Oracle SQL

SQL> with t as 
(select to_date('01/01/2007',
'dd/mm/yyyy') as update_date from dual union all
2    select to_date('01/01/2007',
'dd/mm/yyyy') from dual union all
3    select to_date('03/01/2007',
'dd/mm/yyyy') from dual union all
4    select to_date('03/01/2007',
'dd/mm/yyyy') from dual union all
5    select to_date('03/01/2007', 
'dd/mm/yyyy') from dual union all
6    select to_date('04/01/2007', 
'dd/mm/yyyy') from dual union all
7    select to_date('05/01/2007', 
'dd/mm/yyyy') from dual union all
8    select to_date('07/01/2007', 
'dd/mm/yyyy') from dual union all
9    select to_date('07/01/2007', 
'dd/mm/yyyy') from dual)
10  -- end of test data
11  select to_char(x.UPDATE_DATE,  
'YYYY-MM-DD') as update_date, 
DECODE(t.update_date, NULL, 0, count (*)) 
as count
12  from (select to_date('2007-01-01 00:00:00', 
'YYYY-MM-DD HH24:MI:SS')+
(rownum-1) as update_date
13        from   dual
14        connect by rownum <= 
(to_date('2007-02-01 00:00:00', 
'YYYY-MM-DD HH24:MI:SS')-
15             to_date('2007-01-01 00:00:00', 
'YYYY-MM-DD HH24:MI:SS'))) x
16        LEFT OUTER JOIN t 
ON (x.update_date = t.update_date)
17  where x.UPDATE_DATE >= 
to_date('2007-01-01 00:00:00', 
'YYYY-MM-DD HH24:MI:SS')
18  and x.UPDATE_DATE < 
color="navy">'2007-02-01 00:00:00', 
'YYYY-MM-DD HH24:MI:SS')
19  group by to_char(x.UPDATE_DATE, 'YYYY-MM-DD'), 
t.update_date
20  order by 1
21  /

UPDATE_DAT      COUNT
---------- ----------
2007-01-01          2
2007-01-02          0
2007-01-03          3
2007-01-04          1
2007-01-05          1