event.rb

formatted_time_accessor :occurs_at, :occurs_until

formatted_time.rb

#initializer
class ActiveRecord::Base
  def self.formatted_time_accessor(*names)
    names.each do |name|
      define_method("formatted_#{name}") do
        #self[name].formatted_offset.strftime('%m/%d/%Y %I:%M %p')
        self[name].strftime('%m/%d/%Y %I:%M %p')
      end
      define_method("formatted_#{name}=") do |value|
        self[name] = DateTime.strptime(value, '%m/%d/%Y %I:%M %p').to_time
      end
    end
  end
end