Update partial Values

How do I update partial value.

Example:
I have emp table with column hiredate, Hiredate has values like
11-AUG-98
10-OCT-88
12-OCT-88
11-OCT-89
.....
.....

I want to keep the date same but only change year where year = 88 to 2001.
so Result will be as shown below

11-AUG-98
10-OCT-01
12-OCT-01
11-OCT-89
.....
.....

Thanks in advance

update emp
set hiredate = add_months(hiredate,36)
where to_char(hiredate,'YYYY') = 1988;

sorry, 36 months is for 3 years, just put 156 instead of 36

Here is the easy method and Looks Good
Alter session set nls_date_format = 'DD-MON-YYYY';
Update Emp
Set Hiredate = Substr(Hiredate,1,7)||'9999'
Where substr(Hiredate,8) between 1988 and 2001;

This is fine and Provide the year in four digit year that you want to have.

then Issue
Alter session set nls_date_format = 'DD-MON-YY';

Thanks