using dates in pgsql

G'Day to all those pgsql novices out there

I am trying to isolate those records where the active date is at least six
months old

I have no problem if I use

SELECT * from newbuyers
WHERE activedate < '01/01/2003'
ORDER BY last_name

But I want to use a variable in the WHERE option

WHERE activedate < (current date less 188 days)

active date is a database date field

I would like to include the calculation in the WHERE statement, but if I
can't should I create the (current date less 188 days) outside of the sql
and bring it in as a <dtml-sqlvar ...> variable? and if so how?


Thanks to anyone who can help

John Haley