Newbie interface Q: How to deal with date/time with libpq or ecpg?

Hi, I am new to the postgreSQL.

I would like to set up my own WWW server using linux/postgreSQL. Some of
my web applications use many date/time manipulations. For example, I
would like to dynamicly display a date of birth column with specified
format. I could do it on Oracle like this:
SELECT to_date(DateofBirth, 'MM-DD-YYYY') from Employee_tbl where
First_nm = 'Mike';

But how can I receiver this kind of information with specified format in
postgreSQL by using libpq or ecpg?

Thanks in advance!
Mike