URL: http://www.postgresql.org/docs/7.4/static/functions-datetime.html#OPERATORS-DATETIME-TABLE
Finally I found it. How to add one year to a date in PostgreSQL
SELECT
date('now') + interval '1 year' AS today_in_one_year,
date '2003-12-13' + interval '1 year' AS my_next_birthday ;
Both return a TIMESTAMP type.
Comments
UPDATE: It doesn't return a TIMESTAMP type, it's a DATE type (only 4 bytes).
To get a TIMESTAMP you can do this:
SELECT '2003-12-13' + interval '1 year' AS my_next_birthday;