I wrote an article a while back about the different methods for creating a CountDown on a list view, which is essentially what you're looking for:
Warning: This also mentions our own product as a possible solution
How to create a Countdown in a SharePoint list
Here is a summary of the options:
- Designer: Create a custom view in SharePoint Designer.
- Code: Make your own custom field type from scratch.
- SharePoint Highlighter: Buy our product (notably this doesn't currently support Weeks, just Days and/or Months)
More specifically, I also wrote a (similarly product plugging) article on using [Today] in a list view:
How to use [Today] in a SharePoint list
This article gives more background on why [Today] doesn't work:
Unfortunately because of the much larger amount of information
SharePoint has to pass back and forth, it takes a different approach
to updating the data items. It will only update calculated values when
the related item is added or edited.
Consider SharePoint as an overworked secretary; if you ask for a file
to be updated they’ll find it in the filing cabinet, update the
information, and correct anything else that’s awry on the paperwork
while they’re there. If you ask for all the files for people named
“Smith” to be put on your desk, unless you specifically say “And
update the information on every single one while you’re at it”, it’s
not likely they’ll do the extra work for no reason.
It also received the following rave review from the venerable Mike Walsh himself:
I also didn't think much of the way the advert section was written. Information it wasn't - overdone marketing it was.