// Valid date format
        assertTrue(sitemapsHelper.isValidDateFormat("2025-01-01"));
        assertTrue(sitemapsHelper.isValidDateFormat("2025-01-01T12:00:00+00:00"));
        assertTrue(sitemapsHelper.isValidDateFormat(null));
        assertTrue(sitemapsHelper.isValidDateFormat(""));

        // Invalid date format
        assertFalse(sitemapsHelper.isValidDateFormat("2025-1-1"));

    }

    /**
     * Validates a date format (W3C Datetime format).
     * @param date the date to validate
     * @return true if valid, false otherwise
     */
    protected boolean isValidDateFormat(final String date) {
        if (date == null || date.isEmpty()) {
            return true; // Date is optional
        }
        // Basic validation for W3C Datetime format (YYYY-MM-DD or YYYY-MM-DDThh:mm:ss+00:00)