I have an Access table with 3 columns: an AutoNumber "WeeklyID", a fgn key "CampaignID", and a date field "WeekEnded". 
[It looks like this.](http://i.stack.imgur.com/1Tjgz.png)
What I need to accomplish is a method to automatically add 7 days to the date field for each record sharing the same CampaignID. 

So, if there are 3 records with the same Campaign ID and the date associated with the first record is 4/1/2016, I want the date on the second record to be 4/8/2016, and the date on the third record to be 4/15/2016.

I am not sure if this is possible to accomplish via the DateAdd function in Access, so I'm wondering if there is any VBA that can get the job done?