* Added code for BAEL-1899 get start and end of a day (#4567)

core-java-8/src/main/java/com/baeldung/datetime/UseLocalDate.java

@@ -3,6 +3,7 @@ package com.baeldung.datetime;
 import java.time.DayOfWeek;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
+import java.time.LocalTime;
 import java.time.temporal.ChronoUnit;
 import java.time.temporal.TemporalAdjusters;
 
@@ -43,4 +44,30 @@ class UseLocalDate {
         LocalDateTime startofDay = localDate.atStartOfDay();
         return startofDay;
     }
+
+    LocalDateTime getStartOfDayOfLocalDate(LocalDate localDate) {
+        LocalDateTime startofDay = LocalDateTime.of(localDate, LocalTime.MIDNIGHT);
+        return startofDay;
+    }
+
+    LocalDateTime getStartOfDayAtMinTime(LocalDate localDate) {
+        LocalDateTime startofDay = localDate.atTime(LocalTime.MIN);
+        return startofDay;
+    }
+
+    LocalDateTime getStartOfDayAtMidnightTime(LocalDate localDate) {
+        LocalDateTime startofDay = localDate.atTime(LocalTime.MIDNIGHT);
+        return startofDay;
+    }
+
+    LocalDateTime getEndOfDay(LocalDate localDate) {
+        LocalDateTime endOfDay = localDate.atTime(LocalTime.MAX);
+        return endOfDay;
+    }
+
+    LocalDateTime getEndOfDayFromLocalTime(LocalDate localDate) {
+        LocalDateTime endOfDate = LocalTime.MAX.atDate(localDate);
+        return endOfDate;
+    }
+
 }

core-java-8/src/main/java/com/baeldung/datetime/UseLocalDateTime.java

@@ -1,6 +1,8 @@
 package com.baeldung.datetime;
 
 import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.time.temporal.ChronoField;
 
 public class UseLocalDateTime {
 
@@ -8,4 +10,15 @@ public class UseLocalDateTime {
         return LocalDateTime.parse(representation);
     }
 
+    LocalDateTime getEndOfDayFromLocalDateTimeDirectly(LocalDateTime localDateTime) {
+        LocalDateTime endOfDate = localDateTime.with(ChronoField.NANO_OF_DAY, LocalTime.MAX.toNanoOfDay());
+        return endOfDate;
+    }
+
+    LocalDateTime getEndOfDayFromLocalDateTime(LocalDateTime localDateTime) {
+        LocalDateTime endOfDate = localDateTime.toLocalDate()
+            .atTime(LocalTime.MAX);
+        return endOfDate;
+    }
+
 }

core-java-8/src/main/java/com/baeldung/datetime/UseZonedDateTime.java

@@ -1,12 +1,42 @@
 package com.baeldung.datetime;
 
+import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.ZoneId;
 import java.time.ZonedDateTime;
+import java.time.temporal.ChronoField;
 
 class UseZonedDateTime {
 
     ZonedDateTime getZonedDateTime(LocalDateTime localDateTime, ZoneId zoneId) {
         return ZonedDateTime.of(localDateTime, zoneId);
     }
+
+    ZonedDateTime getStartOfDay(LocalDate localDate, ZoneId zone) {
+        ZonedDateTime startofDay = localDate.atStartOfDay()
+            .atZone(zone);
+        return startofDay;
+    }
+
+    ZonedDateTime getStartOfDayShorthand(LocalDate localDate, ZoneId zone) {
+        ZonedDateTime startofDay = localDate.atStartOfDay(zone);
+        return startofDay;
+    }
+
+    ZonedDateTime getStartOfDayFromZonedDateTime(ZonedDateTime zonedDateTime) {
+        ZonedDateTime startofDay = zonedDateTime.toLocalDateTime()
+            .toLocalDate()
+            .atStartOfDay(zonedDateTime.getZone());
+        return startofDay;
+    }
+
+    ZonedDateTime getStartOfDayAtMinTime(ZonedDateTime zonedDateTime) {
+        ZonedDateTime startofDay = zonedDateTime.with(ChronoField.HOUR_OF_DAY, 0);
+        return startofDay;
+    }
+
+    ZonedDateTime getStartOfDayAtMidnightTime(ZonedDateTime zonedDateTime) {
+        ZonedDateTime startofDay = zonedDateTime.with(ChronoField.NANO_OF_DAY, 0);
+        return startofDay;
+    }
 }