how to record only part of a show?

I like to watch the Today show in the morning while I get ready for work, but I only want to record the first 30 minutes of the 4 hour show. 30 minutes in, it turns into the housewife show which I have no interest in, but the first 30 minutes has a good recap of the the news of the previous day and overnight.

Is there a way to do this? It lets you record longer than a show is, but it seems there is no option to end the recording early.

Any ideas?