I created a table where I want to have two columns with dates. The first will be the date the record in the table is created. The other should be a week later. The table is for a contact management system where I'm going to keep information about when I emailed a contact and when I should follow up a week later.
In Postgres this turned out to be very easy. Look at the following table definition. You can easily create a date 7 days from now by adding "interval '7 days'" to now();
create table campaign_event ( id serial, campaign_id int, contact_id int, add_date timestamp default now(), sent_flag boolean default false, followup_date timestamp default now() + interval '7 days', followup_flag boolean default false );