From babe8e87de8c8a1ba01c0552748c16245545d553 Mon Sep 17 00:00:00 2001
From: Al Niyas <al1niyas@yahoo.com>
Date: Wed, 18 Dec 2019 22:12:16 +0300
Subject: [PATCH] BAEL-3632 Using Instant to check if Two Java Dates are On
 Same Day

---
 .../baeldung/date/comparison/DateComparisonUtils.java  | 10 ++++++++++
 .../date/comparison/DateComparisonUtilsUnitTest.java   | 10 +++++++---
 2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/core-java-modules/core-java-date-operations/src/main/java/com/baeldung/date/comparison/DateComparisonUtils.java b/core-java-modules/core-java-date-operations/src/main/java/com/baeldung/date/comparison/DateComparisonUtils.java
index ae8d21c29c..fea268964a 100644
--- a/core-java-modules/core-java-date-operations/src/main/java/com/baeldung/date/comparison/DateComparisonUtils.java
+++ b/core-java-modules/core-java-date-operations/src/main/java/com/baeldung/date/comparison/DateComparisonUtils.java
@@ -1,8 +1,10 @@
 package com.baeldung.date.comparison;
 
 import java.text.SimpleDateFormat;
+import java.time.Instant;
 import java.time.LocalDate;
 import java.time.ZoneId;
+import java.time.temporal.ChronoUnit;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.TimeZone;
@@ -23,6 +25,14 @@ public class DateComparisonUtils {
         return localDate1.isEqual(localDate2);
     }
 
+    public static boolean isSameDayUsingInstant(Date date1, Date date2) {
+        Instant instant1 = date1.toInstant()
+            .truncatedTo(ChronoUnit.DAYS);
+        Instant instant2 = date2.toInstant()
+            .truncatedTo(ChronoUnit.DAYS);
+        return instant1.equals(instant2);
+    }
+
     public static boolean isSameDayUsingSimpleDateFormat(Date date1, Date date2) {
         SimpleDateFormat fmt = new SimpleDateFormat("yyyyMMdd");
         return fmt.format(date1)
diff --git a/core-java-modules/core-java-date-operations/src/test/java/com/baeldung/date/comparison/DateComparisonUtilsUnitTest.java b/core-java-modules/core-java-date-operations/src/test/java/com/baeldung/date/comparison/DateComparisonUtilsUnitTest.java
index db55aadcca..faa2b18c91 100644
--- a/core-java-modules/core-java-date-operations/src/test/java/com/baeldung/date/comparison/DateComparisonUtilsUnitTest.java
+++ b/core-java-modules/core-java-date-operations/src/test/java/com/baeldung/date/comparison/DateComparisonUtilsUnitTest.java
@@ -1,13 +1,13 @@
 package com.baeldung.date.comparison;
 
-import org.junit.Test;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
 
 import java.time.LocalDateTime;
 import java.time.ZoneId;
 import java.util.Date;
 
-import static org.junit.Assert.assertFalse;
-import static org.junit.Assert.assertTrue;
+import org.junit.Test;
 
 public class DateComparisonUtilsUnitTest {
 
@@ -23,6 +23,7 @@ public class DateComparisonUtilsUnitTest {
     @Test
     public void givenDatesWithDifferentTime_whenIsSameDay_thenReturnsTrue() {
         assertTrue(DateComparisonUtils.isSameDayUsingLocalDate(day1Morning, day1Evening));
+        assertTrue(DateComparisonUtils.isSameDayUsingInstant(day1Morning, day1Evening));
         assertTrue(DateComparisonUtils.isSameDayUsingSimpleDateFormat(day1Morning, day1Evening));
         assertTrue(DateComparisonUtils.isSameDayUsingCalendar(day1Morning, day1Evening));
         assertTrue(DateComparisonUtils.isSameDayUsingApacheCommons(day1Morning, day1Evening));
@@ -35,6 +36,9 @@ public class DateComparisonUtilsUnitTest {
         assertFalse(DateComparisonUtils.isSameDayUsingLocalDate(day1Morning, day2Morning));
         assertFalse(DateComparisonUtils.isSameDayUsingLocalDate(day1Evening, day2Morning));
 
+        assertFalse(DateComparisonUtils.isSameDayUsingInstant(day1Morning, day2Morning));
+        assertFalse(DateComparisonUtils.isSameDayUsingInstant(day1Evening, day2Morning));
+
         assertFalse(DateComparisonUtils.isSameDayUsingSimpleDateFormat(day1Morning, day2Morning));
         assertFalse(DateComparisonUtils.isSameDayUsingSimpleDateFormat(day1Evening, day2Morning));