[BAEL-3315] Added missing code snippets from the Java 8 Date/Time article

Also:
- formatted changed files with Eclipse profile
- corrected failing test: givenTwoDatesInJava8_whenDifferentiating_thenWeGetSix

java-dates/src/test/java/com/baeldung/datetime/UseOffsetDateTimeUnitTest.java

@@ -0,0 +1,24 @@
+package com.baeldung.datetime;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.time.LocalDateTime;
+import java.time.Month;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+
+import org.junit.Test;
+
+public class UseOffsetDateTimeUnitTest {
+    private final UseOffsetDateTime subject = new UseOffsetDateTime();
+
+    @Test
+    public void givenAZoneOffSetAndLocalDateTime_whenCombing_thenValidResult() {
+        ZoneOffset offset = ZoneOffset.of("+02:00");
+        LocalDateTime localDateTime = LocalDateTime.of(2015, Month.FEBRUARY, 20, 6, 30);
+
+        OffsetDateTime result = subject.offsetOfLocalDateTimeAndOffset(localDateTime, offset);
+
+        assertThat(result.toString()).isEqualTo("2015-02-20T06:30+02:00");
+    }
+}