From http://stackoverflow.com/questions/32129741/can-you-use-timecop-gem-for-development-in-rails

new_gist_file.rb

# This allows us to set a different date
# in the admin area, and use TimeCop to process each
# request as being on that different date - useful for
# testing different phases of the challenge.
module TimeTravelFilters
  extend ActiveSupport::Concern

  included do
    if Rails.env.development? || Rails.env.staging?
      around_filter :time_travel_for_request
    end
  end

  def time_travel_for_request
    time_travel
    yield
    time_travel_return
  end

  def time_travel
    logger.info 'TIME TRAVEL START'
    if session[:timecop_date]
      Timecop.travel(session[:timecop_date])
    else
      Timecop.return
    end
  end

  def time_travel_return
    logger.info 'TIME TRAVEL RETURN'
    Timecop.return
  end
end