*
     * @param value the date string to parse
     * @return parsed Date object, or null if parsing fails
     */
    public static Date parseDate(final String value) {
        return parseDate(value, Constants.DATE_OPTIONAL_TIME);
    }

    /**
     * Parses a date string using the specified format.
     *
     * @param value the date string to parse

rue,\"readFromDocValues\":true},{\"name\":\"clientIp\",\"type\":\"string\",\"esTypes\":[\"keyword\"],\"count\":0,\"scripted\":false,\"searchable\":true,\"aggregatable\":true,\"readFromDocValues\":true},{\"name\":\"createdAt\",\"type\":\"date\",\"esTypes\":[\"date\"],\"count\":0,\"scripted\":false,\"searchable\":true,\"aggregatable\":true,\"readFromDocValues\":true},{\"name\":\"docId\",\"type\":\"string\",\"esTypes\":[\"keyword\"],\"count\":0,\"scripted\":false,\"searchable\":true,\"aggregatable\...

  <function>
    <description>
      Returns Date from a given value.
    </description>
    <name>date</name>
    <function-class>org.codelibs.fess.taglib.FessFunctions</function-class>
    <function-signature>java.util.Date date(java.lang.Long)</function-signature>
    <example>
      ${fe:date(doc.tstamp)}
    </example>
  </function>

  <function>
    <description>
      Returns Date from a given value.
    </description>

        assertEquals("\"boolKey\":\"true\"", buf.toString());
    }

    // Test append method with Date value (other object type)
    @Test
    public void test_append_dateValue() {
        StringBuilder buf = new StringBuilder();
        Date date = new Date(1609459200000L);
        Supplier<Object> supplier = () -> date;

        monitorTarget.append(buf, "dateKey", supplier);
        String result = buf.toString();

        assertEquals("Unicode characters should be preserved", original, deserialized);
    }

    /**
     * Test serialization of Date objects
     */
    @Test
    public void test_serializeDeserialize_date() {
        Date original = new Date();

        byte[] serialized = serializer.fromObjectToBinary(original);
        assertNotNull(serialized, "Serialized data should not be null");

    @Test
    public void test_ofNullable_withDate() {
        Date testValue = new Date();
        OptionalEntity<Date> result = OptionalUtil.ofNullable(testValue);

        assertNotNull(result);
        assertTrue(result.isPresent());
        assertEquals(testValue, result.get());
    }

    @Test
    public void test_ofNullable_withNullDate() {
        Date testValue = null;

        }

        return processFieldConfigs(dataMap, fieldConfigs);
    }

    /**
     * Get the last modified date.
     * @param dataMap The data map.
     * @param responseData The response data.
     * @return The last modified date.
     */
    protected Date getLastModified(final Map<String, Object> dataMap, final ResponseData responseData) {

    }

    /**
     * Calculates the document expiration date based on crawling configuration.
     * If the config has a timeToLive value, calculates expiration from current time.
     * Otherwise, returns the stored document expiration time.
     *
     * @param config the crawling configuration containing time-to-live settings
     * @return the document expiration date, or null if no expiration is set
     */

    protected String toRangeDateString(Date date, String format) {
        if (format.contains("epoch_millis")) {
            return Long.toString(date.getTime());
        } else if (format.contains("date_optional_time")) {
            final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
            sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
            return sdf.format(date);
        } else {

    protected String toRangeDateString(Date date, String format) {
        if (format.contains("epoch_millis")) {
            return Long.toString(date.getTime());
        } else if (format.contains("date_optional_time")) {
            final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss");
            sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
            return sdf.format(date);
        } else {