I had that originally, but if it's `nil`, `Time.at` will barf and you don't really want to do `TIme.at(0)` for `nil`, since it's kind of a lie.

And, if you jump through those hoops and get a `Time` or `nil`, then in the template, you have to call `to_i` on  the `Time` to make it an int, but calling `to_i` on `nil` is `0`, so you have more hoops... I figured this was way simpler. If it causes pain down the road, we can make it nicer in some way, IMO.