code: public ColumnConfig setValueDate(String valueDate) throws DateParseException {
          if ((valueDate == null) || "null".equalsIgnoreCase(valueDate)) {
              this.valueDate = null;
          } else if (NowAndTodayUtil.isNowOrTodayFormat(valueDate)) {
              this.valueDate = NowAndTodayUtil.doNowOrToday(valueDate, this.getType());
          } else {
              try {
                  this.valueDate = new ISODateFormat().parse(valueDate);
              } catch (ParseException e) {
                  //probably a function
                  this.valueComputed = new DatabaseFunction(valueDate);
              }
          }
  
          return this;
      }
docs: Set the date this column should be set to. Supports any of the date or datetime formats handled by {@link ISODateFormat}.
  If the passed value cannot be parsed as a date, it is assumed to be a function that returns a date.
  If the string "null" is passed, it will set a null value.
  @param valueDate the Date Value to use (may be null or "null", or start with "now" or "today".
  @throws DateParseException if the columnType isn't supported for "now" or "today" values.