 The tone of list provision was amended in 1981 to provide that the rateable value was to be ascertained by reference to the value as at a designated date known as the “relevant date”.General changes in value after the relevant date are not material, so any increase or reduction in value since that date would not affect the rateable values.In recent years, the relevant date has been fixed at 1 October for the Valuation List to take effect on 1 April in the following year, i.e.