Question

Following Ryan Bates’ instructions on creating a before_filter that sets a time_zone like so :

before_filter :set_timezone

def set_timezone
    Time.zone = @current_user.time_zone
end

Why does this not affect, let’s say, another user using the same application at the same time in different timezone?

Answer 1

Because even Rails app can have many threads, each thread maintains its own zone. So, from the time you clicked a link and till you got the response body you were exclusively dealing with the same thread (i.e. with the same zone).