diff --git a/core-java/README.md b/core-java/README.md
index dabf6f39be..a4b5127e98 100644
--- a/core-java/README.md
+++ b/core-java/README.md
@@ -141,3 +141,6 @@
- [Guide to UUID in Java](http://www.baeldung.com/java-uuid)
- [How to Get the Last Element of a Stream in Java?](http://www.baeldung.com/java-stream-last-element)
- [Guide to Escaping Characters in Java RegExps](http://www.baeldung.com/java-regexp-escape-char)
+- [Period and Duration in Java](http://www.baeldung.com/java-period-duration)
+- [Introduction to the Java 8 Date/Time API](http://www.baeldung.com/java-8-date-time-intro)
+- [Migrating to the New Java 8 Date Time API](http://www.baeldung.com/migrating-to-java-8-date-time-api)
diff --git a/core-java/pom.xml b/core-java/pom.xml
index 422965a0ed..586486027a 100644
--- a/core-java/pom.xml
+++ b/core-java/pom.xml
@@ -186,6 +186,16 @@
fscontext
${fscontext.version}
+
+ joda-time
+ joda-time
+ ${joda-time.version}
+
+
+ com.darwinsys
+ hirondelle-date4j
+ ${hirondelle-date4j.version}
+
@@ -408,6 +418,8 @@
1.8.7
1.16.12
4.6-b01
+ 2.9.9
+ 1.5.1
1.3
@@ -416,9 +428,9 @@
3.6.1
1.7.0
+
3.6.0
2.19.1
-
diff --git a/core-java/src/test/java/com/baeldung/DateDiffUnitTest.java b/core-java/src/test/java/com/baeldung/DateDiffUnitTest.java
new file mode 100644
index 0000000000..40b7fac30d
--- /dev/null
+++ b/core-java/src/test/java/com/baeldung/DateDiffUnitTest.java
@@ -0,0 +1,63 @@
+package com.baeldung;
+
+import org.joda.time.DateTime;
+import org.junit.Test;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.time.Duration;
+import java.time.ZonedDateTime;
+import java.util.Date;
+import java.util.Locale;
+import java.util.TimeZone;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.assertEquals;
+
+public class DateDiffUnitTest {
+
+ @Test
+ public void givenTwoDatesBeforeJava8_whenDifferentiating_thenWeGetSix() throws ParseException {
+ SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy", Locale.ENGLISH);
+ Date firstDate = sdf.parse("06/24/2017");
+ Date secondDate = sdf.parse("06/30/2017");
+
+ long diffInMillies = Math.abs(secondDate.getTime() - firstDate.getTime());
+ long diff = TimeUnit.DAYS.convert(diffInMillies, TimeUnit.MILLISECONDS);
+
+ assertEquals(diff, 6);
+ }
+
+ @Test
+ public void givenTwoDatesInJava8_whenDifferentiating_thenWeGetSix() {
+ ZonedDateTime now = ZonedDateTime.now();
+ ZonedDateTime sixDaysBehind = now.minusDays(6);
+
+ Duration duration = Duration.between(now, sixDaysBehind);
+ long diff = Math.abs(duration.toDays());
+
+ assertEquals(diff, 6);
+ }
+
+ @Test
+ public void givenTwoDatesInJodaTime_whenDifferentiating_thenWeGetSix() {
+ DateTime now = DateTime.now();
+ DateTime sixDaysBehind = now.minusDays(6);
+
+ org.joda.time.Duration duration = new org.joda.time.Duration(now, sixDaysBehind);
+ long diff = Math.abs(duration.getStandardDays());
+
+ assertEquals(diff, 6);
+ }
+
+ @Test
+ public void givenTwoDatesInDate4j_whenDifferentiating_thenWeGetSix() {
+ hirondelle.date4j.DateTime now = hirondelle.date4j.DateTime.now(TimeZone.getDefault());
+ hirondelle.date4j.DateTime sixDaysBehind = now.minusDays(6);
+
+ long diff = Math.abs(now.numDaysFrom(sixDaysBehind));
+
+ assertEquals(diff, 6);
+ }
+
+}
\ No newline at end of file
diff --git a/java-difference-date/README.md b/java-difference-date/README.md
new file mode 100644
index 0000000000..2a024c27a2
--- /dev/null
+++ b/java-difference-date/README.md
@@ -0,0 +1,5 @@
+## Relevant articles:
+
+- [Period and Duration in Java](http://www.baeldung.com/java-period-duration)
+- [Introduction to the Java 8 Date/Time API](http://www.baeldung.com/java-8-date-time-intro)
+- [Migrating to the New Java 8 Date Time API](http://www.baeldung.com/migrating-to-java-8-date-time-api)
\ No newline at end of file
diff --git a/java-difference-date/pom.xml b/java-difference-date/pom.xml
new file mode 100644
index 0000000000..388753de90
--- /dev/null
+++ b/java-difference-date/pom.xml
@@ -0,0 +1,58 @@
+
+
+ 4.0.0
+
+ com.baeldung
+ java-difference-date
+ 0.0.1-SNAPSHOT
+ jar
+
+ java-difference-date
+ Difference between two dates in java
+
+
+ com.baeldung
+ parent-modules
+ 1.0.0-SNAPSHOT
+
+
+
+
+ joda-time
+ joda-time
+ ${joda-time.version}
+
+
+ com.darwinsys
+ hirondelle-date4j
+ ${hirondelle-date4j.version}
+
+
+ junit
+ junit
+ ${junit.version}
+ test
+
+
+
+
+
+
+ org.apache.maven.plugins
+ maven-compiler-plugin
+
+ 1.8
+ 1.8
+
+
+
+
+
+
+ 1.8
+ 4.12
+ 2.9.9
+ 1.5.1
+
+
diff --git a/java-difference-date/src/test/java/com/baeldung/DateDiffTest.java b/java-difference-date/src/test/java/com/baeldung/DateDiffTest.java
new file mode 100644
index 0000000000..4203f7ef38
--- /dev/null
+++ b/java-difference-date/src/test/java/com/baeldung/DateDiffTest.java
@@ -0,0 +1,61 @@
+package com.baeldung;
+
+import org.joda.time.DateTime;
+import org.junit.Test;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.time.Duration;
+import java.time.ZonedDateTime;
+import java.util.Date;
+import java.util.Locale;
+import java.util.TimeZone;
+import java.util.concurrent.TimeUnit;
+
+import static org.junit.Assert.assertEquals;
+
+public class DateDiffTest {
+ @Test
+ public void givenTwoDatesBeforeJava8_whenDifferentiating_thenWeGetSix() throws ParseException {
+ SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy", Locale.ENGLISH);
+ Date firstDate = sdf.parse("06/24/2017");
+ Date secondDate = sdf.parse("06/30/2017");
+
+ long diffInMillies = Math.abs(secondDate.getTime() - firstDate.getTime());
+ long diff = TimeUnit.DAYS.convert(diffInMillies, TimeUnit.MILLISECONDS);
+
+ assertEquals(diff, 6);
+ }
+
+ @Test
+ public void givenTwoDatesInJava8_whenDifferentiating_thenWeGetSix() {
+ ZonedDateTime now = ZonedDateTime.now();
+ ZonedDateTime sixDaysBehind = now.minusDays(6);
+
+ Duration duration = Duration.between(now, sixDaysBehind);
+ long diff = Math.abs(duration.toDays());
+
+ assertEquals(diff, 6);
+ }
+
+ @Test
+ public void givenTwoDatesInJodaTime_whenDifferentiating_thenWeGetSix() {
+ DateTime now = DateTime.now();
+ DateTime sixDaysBehind = now.minusDays(6);
+
+ org.joda.time.Duration duration = new org.joda.time.Duration(now, sixDaysBehind);
+ long diff = Math.abs(duration.getStandardDays());
+
+ assertEquals(diff, 6);
+ }
+
+ @Test
+ public void givenTwoDatesInDate4j_whenDifferentiating_thenWeGetSix() {
+ hirondelle.date4j.DateTime now = hirondelle.date4j.DateTime.now(TimeZone.getDefault());
+ hirondelle.date4j.DateTime sixDaysBehind = now.minusDays(6);
+
+ long diff = Math.abs(now.numDaysFrom(sixDaysBehind));
+
+ assertEquals(diff, 6);
+ }
+}
\ No newline at end of file