def maintenance_window
      return nil if maintenance_weekday.nil?
      weekday = Date::DAYNAMES[maintenance_weekday]
      sprintf("%s %02d:00 UTC", weekday, maintenance_hour)
    end
def maintenance_window
      return nil if maintenance_weekday.nil?
      weekday = Date::DAYNAMES[maintenance_weekday]
      sprintf("%s %02d:00 UTC", weekday, maintenance_hour)
    end
A more humanised version of the maintenance window