Can I restrict the times during which iTunes downloads podcast content?
What you need to do is refresh the podcasts at a time during the download period and then set the update podcast to &quot;Daily&quot;
Find the settings button :-

And select Daily..

This is because the Daily refresh will reset itself to download every 24 hours after that time..
As seen here I refreshed this morning and the next update will be 24 hours after that.

The caveat, of course, is that iTunes must be running at the time you want it to refresh