This isn't a great answer to your question, but with the new ad pause feature, you could create a series of ads with new dates in them once a week or so, and then pause them. Then each day you could unpause the appropriate one.
Alternatively you could create 7 campaigns each using the scheduling feature. Set each one to run one day a week. Then once a week you could go in and modify all 7 ads. This way you wouldnt have to worry about them on a daily basis.