Bug 146709 Dates still do not work from main report to sub reports...
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/util/ParameterValidationUtil.java
static private Number doValidateNumberByPattern( String dataType,
			String format, String value, ULocale locale )
			throws ValidationValueException
	{
		assert DesignChoiceConstants.PARAM_TYPE_FLOAT
				.equalsIgnoreCase( dataType )
				|| DesignChoiceConstants.PARAM_TYPE_DECIMAL
						.equalsIgnoreCase( dataType );
		if ( DesignChoiceConstants.NUMBER_FORMAT_TYPE_UNFORMATTED
				.equalsIgnoreCase( format ) )
			return doValidateNumber( dataType, value, locale );
		assert !StringUtil.isBlank( format );
		if ( StringUtil.isBlank( value ) )
			return null;
		NumberFormatter formatter = new NumberFormatter( locale );
		formatter.applyPattern( format );
		try
		{
			return formatter.parse( value );
		}
		catch ( ParseException e )
		{
			throw new ValidationValueException( value,
					PropertyValueException.DESIGN_EXCEPTION_INVALID_VALUE,
					dataType );
		}
	}
	/**
	 * Gets the display string for the value with the given data type, format,
	 * locale. The value must be the valid data type. That is: