Add TCK tests

tck/src/main/java/com/sun/ts/tests/el/spec/relationaloperator/DateTimeOperandsIT.java

diff --git a/tck/src/main/java/com/sun/ts/tests/el/spec/relationaloperator/DateTimeOperandsIT.java b/tck/src/main/java/com/sun/ts/tests/el/spec/relationaloperator/DateTimeOperandsIT.java
new file mode 100644
index 0000000..670e296
--- /dev/null
+++ b/tck/src/main/java/com/sun/ts/tests/el/spec/relationaloperator/DateTimeOperandsIT.java
@@ -0,0 +1,145 @@
+/*
+ * Copyright (c) 2025 Contributors to the Eclipse Foundation
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0, which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ *
+ * This Source Code may also be made available under the following Secondary
+ * Licenses when the conditions for such availability set forth in the
+ * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
+ * version 2 with the GNU Classpath Exception, which is available at
+ * https://www.gnu.org/software/classpath/license.html.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
+ */
+package com.sun.ts.tests.el.spec.relationaloperator;
+
+import java.lang.System.Logger;
+import java.time.Clock;
+import java.time.Instant;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+import java.util.Collections;
+import java.util.Date;
+import java.util.List;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import com.sun.ts.tests.el.common.util.ExprEval;
+import com.sun.ts.tests.el.common.util.NameValuePair;
+import com.sun.ts.tests.el.common.util.TestNum;
+
+public class DateTimeOperandsIT {
+
+    private static final Logger logger = System.getLogger(DateTimeOperandsIT.class.getName());
+
+    private List<Object> dateTimeList = Collections.unmodifiableList(TestNum.getDateTimeList());
+
+
+    @Test
+    public void elDateTest() throws Exception {
+        doTypeTest(x -> Date.from(x));
+    }
+
+    @Test
+    public void elClockTest() throws Exception {
+        doTypeTest(x -> Clock.fixed(x, ZoneId.of("Z")));
+    }
+
+    @Test
+    public void elInstantTest() throws Exception {
+        doTypeTest(x -> x);
+    }
+
+    @Test
+    public void elTemporalTest() throws Exception {
+        doTypeTest(x -> ZonedDateTime.ofInstant(x, ZoneId.of("+12:00")));
+    }
+
+    @Test
+    public void elStringTest() throws Exception {
+        doTypeTest(x -> x.toString());
+    }
+
+    private void doTypeTest(InstantToObject converter) {
+        doEqualToTest(converter);
+        doNotEqualToTest(converter);
+        doLessThanTest(converter);
+        doLessThanOrEqualTest(converter);
+        doGreaterThanOrEqualTest(converter);
+        doGreaterThanTest(converter);
+    }
+
+
+    private void doEqualToTest(InstantToObject converter) {
+        doTest(converter, List.of("==", "eq"), Boolean.FALSE, Boolean.TRUE, Boolean.FALSE);
+    }
+
+
+    private void doNotEqualToTest(InstantToObject converter) {
+        doTest(converter, List.of("!=", "ne"), Boolean.TRUE, Boolean.FALSE, Boolean.TRUE);
+    }
+
+
+    private void doLessThanTest(InstantToObject converter) {
+        doTest(converter, List.of("<", "lt"), Boolean.TRUE, Boolean.FALSE, Boolean.FALSE);
+    }
+
+
+    private void doLessThanOrEqualTest(InstantToObject converter) {
+        doTest(converter, List.of("<=", "le"), Boolean.TRUE, Boolean.TRUE, Boolean.FALSE);
+    }
+
+
+    private void doGreaterThanOrEqualTest(InstantToObject converter) {
+        doTest(converter, List.of(">=", "ge"), Boolean.FALSE, Boolean.TRUE, Boolean.TRUE);
+    }
+
+
+    private void doGreaterThanTest(InstantToObject converter) {
+        doTest(converter, List.of(">", "gt"), Boolean.FALSE, Boolean.FALSE, Boolean.TRUE);
+    }
+
+    private void doTest(InstantToObject converter, List<String> operators, Boolean beforeResult, Boolean equalResult,
+            Boolean afterResult) {
+        for (String operator : operators) {
+            // Value passed in is before the reference date.
+            testOperatorRelational(converter.toObject(TestNum.DATE_REFERENCE_BEFORE), beforeResult, operator);
+
+            // Value passed in is equal to the reference date.
+            testOperatorRelational(converter.toObject(TestNum.DATE_REFERENCE), equalResult, operator);
+
+            // Value passed in is after the reference date.
+            testOperatorRelational(converter.toObject(TestNum.DATE_REFERENCE_AFTER), afterResult, operator);
+        }
+    }
+
+
+    private void testOperatorRelational(Object testValue, Boolean expectedResult, String operator) {
+
+        for (Object testDateTime : dateTimeList) {
+            NameValuePair values[] = NameValuePair.buildNameValuePair(testValue, testDateTime);
+
+            try {
+                String expr = ExprEval.buildElExpr(false, operator);
+                logger.log(Logger.Level.TRACE, "expression to be evaluated is " + expr);
+                logger.log(Logger.Level.TRACE, "types are " + testValue.getClass().getName() + " and " +
+                        testDateTime.getClass().getName());
+
+                Object result = ExprEval.evaluateValueExpression(expr, values, Object.class);
+
+                Assertions.assertTrue(ExprEval.compareClass(result, Boolean.class));
+                Assertions.assertEquals(result, expectedResult);
+            } finally {
+                ExprEval.cleanup();
+            }
+        }
+    }
+
+
+    @FunctionalInterface
+    public interface InstantToObject {
+        Object toObject(Instant instant);
+    }
+}