Signed and Permanent Cookies in Rails 3

Looks like a cool feature, but I haven't yet gotten into Ruby or Rails. I do have one question, though. There is an interesting looking language feature I see: <i>20.years.from_now.utc</i>. I would presume that to mean "20 years from this time in zulu". So presuming that <i>20.years.from_now.cdt</i> means central daylight time, is that a different time?<p>To put the question a little shorter, isn't the concept of "20 years from now" independent of time zone, or am I missing something?

I feel like I'm not understanding something. How is this "signed"? It appears they're just storing the user's salt in their cookie... in which case you might as well store any other random info, it doesn't mean it's "signed", it just prevents people from changing their cookie's user_id and logging in as someone else. Didn't they already have something like that in place?

"A whole lot easier" Is this a joke?