active_record_extensions.rb

# class Event
#   parse_dates :start_date, :end_date
# end

class ActiveRecord::Base

  def self.parse_dates(*args)
    args.flatten.each do |method_name|
      class_eval do
        define_method "#{method_name}=" do |date|
          return super(date) unless date.kind_of?(String)
          if self.respond_to?(:timezone) and self.timezone.present?
            if date.match('UTC')
              self.timezone = 'UTC'
            end
            Time.zone = self.timezone 
            Chronic.time_class = Time.zone
          end
          super((Chronic.parse(date) rescue nil) || (Time.zone.parse(date) rescue nil) || date)
        end
      end
    end
  end
end