diff --git a/core-java/src/test/java/com/baeldung/java/clock/ClockUnitTest.java b/core-java/src/test/java/com/baeldung/java/clock/ClockUnitTest.java
new file mode 100644
index 0000000000..e83ba7afc8
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/java/clock/ClockUnitTest.java
@@ -0,0 +1,159 @@
+package com.baeldung.java.clock;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.time.Clock;
+import java.time.Duration;
+import java.time.ZoneId;
+import java.time.ZoneOffset;
+
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ClockUnitTest {
+
+	private static final Logger LOGGER = LoggerFactory.getLogger(ClockUnitTest.class);
+
+	@Test
+	public void givenClock_withSytemUTC_retrievesInstant() {
+		
+		Clock clockUTC = Clock.systemUTC();
+
+		assertEquals(clockUTC.getZone(), ZoneOffset.UTC);
+		assertEquals(clockUTC.instant().equals(null), false);
+
+		LOGGER.debug("UTC instant :: " + clockUTC.instant());
+	}
+
+	@Test
+	public void givenClock_withSytem_retrievesInstant() {
+
+		Clock clockSystem = Clock.system(ZoneId.of("Asia/Calcutta"));
+
+		assertEquals(clockSystem.getZone(), ZoneId.of("Asia/Calcutta"));
+		assertEquals(clockSystem.instant().equals(null), false);
+
+		LOGGER.debug("System zone :: " + clockSystem.getZone());
+	}
+
+	@Test
+	public void givenClock_withSytemDefaultZone_retrievesInstant() {
+		
+		Clock clockSystemDefault = Clock.systemDefaultZone();
+
+		assertEquals(clockSystemDefault.getZone().equals(null), false);
+		assertEquals(clockSystemDefault.instant().equals(null), false);
+
+		LOGGER.debug("System Default instant :: " + clockSystemDefault.instant());
+	}
+
+	@Test
+	public void givenClock_withSytemUTC_retrievesTimeInMillis() {
+		
+		Clock clockMillis = Clock.systemDefaultZone();
+
+		assertEquals(clockMillis.instant().equals(null), false);
+		assertTrue(clockMillis.millis() > 0);
+
+		LOGGER.debug("System Default millis :: " + clockMillis.millis());
+	}
+
+	@Test
+	public void givenClock_usingOffset_retrievesFutureDate() {
+		
+		Clock baseClock = Clock.systemDefaultZone();
+
+		// result clock will be later than baseClock
+		Clock futureClock = Clock.offset(baseClock, Duration.ofHours(72));
+
+		assertEquals(futureClock.instant().equals(null), false);
+		assertTrue(futureClock.millis() > baseClock.millis());
+
+		LOGGER.debug("Future Clock instant :: " + futureClock.instant());
+	}
+
+	@Test
+	public void givenClock_usingOffset_retrievesPastDate() {
+		Clock baseClock = Clock.systemDefaultZone();
+
+		// result clock will be later than baseClock
+		Clock pastClock = Clock.offset(baseClock, Duration.ofHours(-72));
+
+		assertEquals(pastClock.instant().equals(null), false);
+		assertTrue(pastClock.millis() < baseClock.millis());
+
+		LOGGER.debug("Past Clock instant :: " + pastClock.instant());
+	}
+
+	@Test
+	public void givenClock_usingTick_retrievesInstant() {
+		Clock clockDefaultZone = Clock.systemDefaultZone();
+		Clock clocktick = Clock.tick(clockDefaultZone, Duration.ofSeconds(300));
+
+		assertEquals(clockDefaultZone.instant().equals(null), false);
+		assertEquals(clocktick.instant().equals(null), false);
+		assertTrue(clockDefaultZone.millis() > clocktick.millis());
+
+		LOGGER.debug("Clock Default Zone instant : " + clockDefaultZone.instant());
+		LOGGER.debug("Clock tick instant: " + clocktick.instant());
+	}
+
+	@Test(expected=IllegalArgumentException.class)
+	public void givenClock_usingTickDurationNegative_throwsException() {
+		
+		Clock clockDefaultZone = Clock.systemDefaultZone();
+		Clock.tick(clockDefaultZone, Duration.ofSeconds(-300));
+
+	}
+	
+	@Test
+	public void givenClock_usingTickSeconds_retrievesInstant() {
+		ZoneId zoneId = ZoneId.of("Asia/Calcutta");
+		Clock tickSeconds = Clock.tickSeconds(zoneId);
+
+		assertEquals(tickSeconds.instant().equals(null), false);
+		LOGGER.debug("Clock tick seconds instant :: " + tickSeconds.instant());
+
+		tickSeconds = Clock.tick(Clock.system(ZoneId.of("Asia/Calcutta")), Duration.ofSeconds(100));
+		assertEquals(tickSeconds.instant().equals(null), false);
+	}
+
+	@Test
+	public void givenClock_usingTickMinutes_retrievesInstant() {
+		
+		Clock tickMinutes = Clock.tickMinutes(ZoneId.of("Asia/Calcutta"));
+
+		assertEquals(tickMinutes.instant().equals(null), false);
+		LOGGER.debug("Clock tick seconds instant :: " + tickMinutes.instant());
+
+		tickMinutes = Clock.tick(Clock.system(ZoneId.of("Asia/Calcutta")), Duration.ofMinutes(5));
+		assertEquals(tickMinutes.instant().equals(null), false);
+	}
+
+	@Test
+	public void givenClock_usingWithZone_retrievesInstant() {
+		
+		ZoneId zoneSingapore = ZoneId.of("Asia/Singapore");
+		Clock clockSingapore = Clock.system(zoneSingapore);
+
+		assertEquals(clockSingapore.instant().equals(null), false);
+		LOGGER.debug("clockSingapore instant : " + clockSingapore.instant());
+
+		ZoneId zoneCalcutta = ZoneId.of("Asia/Calcutta");
+		Clock clockCalcutta = clockSingapore.withZone(zoneCalcutta);
+		assertEquals(clockCalcutta.instant().equals(null), false);
+		LOGGER.debug("clockCalcutta instant : " + clockSingapore.instant());
+	}
+
+	@Test
+	public void givenClock_usingGetZone_retrievesZoneId() {
+		
+		Clock clockDefaultZone = Clock.systemDefaultZone();
+		ZoneId zone = clockDefaultZone.getZone();
+
+		assertEquals(zone.getId().equals(null), false);
+		LOGGER.debug("Default zone instant : " + clockDefaultZone.instant());
+	}
+}