Are questions that will go out of date "on topic" for this site?
For example, the answers to the question Is it safe to travel to Japan due to the nuclear situation? could conceivably become incorrect as time goes on.
Should we accept such questions on this site?
Yes, because you don't know for how long it won't be relevant. Also, the question is only time-relevant for people planning to travel there, but who knows what value questions like those have for future users (perhaps for someone doing a report, or if a similar event happened).
I would say if it has broad enough value currently, even if only for a year, it's a decent question.
StackExchange websites do not need to only hold perpetually true information.
For instance, Webapps questions become irrelevant extremely fast, as most websites change their features/rules very often.
I would say, for most of the questions asked on this site, they WILL be time relevant. Visa information changes on a yearly basis. Revolutions/uprising/crime changes constantly. I think this site needs to accept time based questions.
Don't be so pessimistic. There could be another nuclear incident and then some of the information (eg about lettuce) would be relevant again!
The questions, that are accurate now, and may change in the future, but we don't know when exactly, should be fine here.
Questions that are specific only to a certain point in time, (like concerning value of exchange rate, current, non-recurring events), should be closed as "too localized".
