7.3RC2 does not have datetime() function?

Don't know if this is a bug or not but ... this query worked under 7.2.1
but doesn't under 7.3RC2. datetime was a built-in function ...

$ psql JC -c "select to_char(datetime(upload_time),'YYYY-MM-DD') as
utime from products where id='989000627108' "
ERROR:  Function datetime(timestamp without time zone) does not exist
         Unable to identify a function that satisfies the given argument
types
         You may need to add explicit typecasts

JC