Recurring Date

Here's my problem:

I have a date that is entered into the field, 12/17/2004. My client wants the site set up so that when after the date is entered, it automatically updates itself every week. So the date represents an event, and he wants to update the event date automatically instead of having a user login and update the date manually. So 12.17/2004 shoudl turn into 12/24/2004, and then 12/31/2004 and so forth.

One brilliant guy told me that if you entered a start date of and an end date then some how that might me be a little easier.

Any thoughts good people?