I am building an app for a client that will have 30 days of content for free, thereafter you are required to buy a subscription via in app store purchases.
However,
It is difficult to clarify the situation because unfortunately the guidelines are not necessarily set in stone. They can and do vary on an app and publisher basis.
In the case of The Times and The Daily, both apps are produced by News Corp. It is perhaps safe to say that News Corp has a good deal more influence with Apple than a one-man development shop producing an iPhone game. Apple would be loath to admit it, but there are clear cases of popular apps on the store that don't conform to the guidelines, where they have tacitly made an exception.
So what I would say to you is this: be sensible. Don't have an app that quits automatically when your trial runs out. Think about what would be acceptable to users. It's very much a case of nothing ventured, nothing gained. Take a risk, submit your app with your limited trial, and see what happens.