DV allows to make use of individual elements of any Date or Datetime column. Thus, there is no need to calculate the Year portion of a Date as an additional column. For this to work correclty the data type must also be of Date or Datetime on the Database. When importing a text (csv) file to a Oracle Database, a Date may be defined as a text (varchar) field by default. In order to make use of this DV Feature, the data type should be changed to Date data type when importing e.g. with SQL Developer. Otherwise, the field containing the Date may just be displayed with a blue “A” like any other attribute, but not with the purple “clock” to identify a true Date field.