Switch from Postgres to H2

java-dates/src/main/java/com/baeldung/date/AgeCalculator.java

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+package com.baeldung.date;
+
+import java.text.DateFormat;
+import java.text.SimpleDateFormat;
+import java.time.LocalDate;
+import java.time.Period;
+import java.util.Date;
+import org.joda.time.Years;
+
+public class AgeCalculator {
+
+    public int calculateAge(LocalDate birthDate, LocalDate currentDate) {
+        // validate inputs ...
+        return Period.between(birthDate, currentDate)
+            .getYears();
+    }
+
+    public int calculateAgeWithJodaTime(org.joda.time.LocalDate birthDate, org.joda.time.LocalDate currentDate) {
+        // validate inputs ...
+        Years age = Years.yearsBetween(birthDate, currentDate);
+        return age.getYears();
+    }
+
+    public int calculateAgeWithJava7(Date birthDate, Date currentDate) {
+        // validate inputs ...
+        DateFormat formatter = new SimpleDateFormat("yyyyMMdd");
+        int d1 = Integer.parseInt(formatter.format(birthDate));
+        int d2 = Integer.parseInt(formatter.format(currentDate));
+        int age = (d2 - d1) / 10000;
+        return age;
+    }
+}

java-dates/src/main/java/com/baeldung/date/DateWithoutTime.java

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+package com.baeldung.date;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.time.LocalDate;
+import java.util.Calendar;
+import java.util.Date;
+
+public class DateWithoutTime {
+
+    public static Date getDateWithoutTimeUsingCalendar() {
+        Calendar calendar = Calendar.getInstance();
+        calendar.set(Calendar.HOUR_OF_DAY, 0);
+        calendar.set(Calendar.MINUTE, 0);
+        calendar.set(Calendar.SECOND, 0);
+        calendar.set(Calendar.MILLISECOND, 0);
+
+        return calendar.getTime();
+    }
+
+    public static Date getDateWithoutTimeUsingFormat() throws ParseException {
+        SimpleDateFormat formatter = new SimpleDateFormat("dd/MM/yyyy");
+        return formatter.parse(formatter.format(new Date()));
+    }
+
+    public static LocalDate getLocalDate() {
+        return LocalDate.now();
+    }
+
+}

java-dates/src/main/java/com/baeldung/date/comparison/DateTimeComparisonUtils.java

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+package com.baeldung.date.comparison;
+
+import java.time.LocalDate;
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.time.ZonedDateTime;
+
+import static java.time.temporal.ChronoUnit.*;
+
+public class DateTimeComparisonUtils {
+
+    public static boolean isSameDay(LocalDateTime timestamp, LocalDate localDateToCompare) {
+        return timestamp.toLocalDate().isEqual(localDateToCompare);
+    }
+
+    public static boolean isSameDay(LocalDateTime timestamp, LocalDateTime timestampToCompare) {
+        return timestamp.truncatedTo(DAYS).isEqual(timestampToCompare.truncatedTo(DAYS));
+    }
+
+    public static boolean isSameHour(LocalDateTime timestamp, LocalDateTime timestampToCompare) {
+        return timestamp.truncatedTo(HOURS).isEqual(timestampToCompare.truncatedTo(HOURS));
+    }
+
+    public static boolean isSameMinute(LocalDateTime timestamp, LocalDateTime timestampToCompare) {
+        return timestamp.truncatedTo(MINUTES).isEqual(timestampToCompare.truncatedTo(MINUTES));
+    }
+
+    public static boolean isSameHour(ZonedDateTime zonedTimestamp, ZonedDateTime zonedTimestampToCompare) {
+        return zonedTimestamp.truncatedTo(HOURS).isEqual(zonedTimestampToCompare.truncatedTo(HOURS));
+    }
+
+    public static boolean isSameHour(ZonedDateTime zonedDateTime, LocalDateTime localDateTime, ZoneId zoneId) {
+        return isSameHour(zonedDateTime, localDateTime.atZone(zoneId));
+    }
+}

java-dates/src/main/java/com/baeldung/date/comparison/LegacyDateComparisonUtils.java

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+package com.baeldung.date.comparison;
+
+import org.apache.commons.lang3.time.DateUtils;
+
+import java.util.Calendar;
+import java.util.Date;
+
+public class LegacyDateComparisonUtils {
+
+    public static boolean isSameDay(Date date, Date dateToCompare) {
+        return DateUtils.isSameDay(date, dateToCompare);
+    }
+
+    public static boolean isSameHour(Date date, Date dateToCompare) {
+        return DateUtils.truncatedEquals(date, dateToCompare, Calendar.HOUR);
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/AddHoursToDate.java

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+package com.baeldung.datetime;
+
+import java.time.Duration;
+import java.time.Instant;
+import java.time.LocalDateTime;
+import java.time.ZonedDateTime;
+import java.time.temporal.ChronoUnit;
+import java.util.Calendar;
+import java.util.Date;
+
+import org.apache.commons.lang3.time.DateUtils;
+
+public class AddHoursToDate {
+
+    public Date addHoursToJavaUtilDate(Date date, int hours) {
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+        calendar.add(Calendar.HOUR_OF_DAY, hours);
+        return calendar.getTime();
+    }
+
+    public Date addHoursToDateUsingInstant(Date date, int hours) {
+        return Date.from(date.toInstant()
+            .plus(Duration.ofHours(hours)));
+    }
+
+    public LocalDateTime addHoursToLocalDateTime(LocalDateTime localDateTime, int hours) {
+        return localDateTime.plusHours(hours);
+    }
+
+    public LocalDateTime subtractHoursToLocalDateTime(LocalDateTime localDateTime, int hours) {
+        return localDateTime.minusHours(hours);
+    }
+
+    public ZonedDateTime addHoursToZonedDateTime(ZonedDateTime zonedDateTime, int hours) {
+        return zonedDateTime.plusHours(hours);
+    }
+
+    public ZonedDateTime subtractHoursToZonedDateTime(ZonedDateTime zonedDateTime, int hours) {
+        return zonedDateTime.minusHours(hours);
+    }
+
+    public Instant addHoursToInstant(Instant instant, int hours) {
+        return instant.plus(hours, ChronoUnit.HOURS);
+    }
+
+    public Instant subtractHoursToInstant(Instant instant, int hours) {
+        return instant.minus(hours, ChronoUnit.HOURS);
+    }
+
+    public Date addHoursWithApacheCommons(Date date, int hours) {
+        return DateUtils.addHours(date, hours);
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/DateExtractYearMonthDayIntegerValues.java

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+package com.baeldung.datetime;
+
+import java.util.Calendar;
+import java.util.Date;
+
+public class DateExtractYearMonthDayIntegerValues {
+
+    int getYear(Date date) {
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+
+        return calendar.get(Calendar.YEAR);
+    }
+
+    int getMonth(Date date) {
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+
+        return calendar.get(Calendar.MONTH);
+    }
+
+    int getDay(Date date) {
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+
+        return calendar.get(Calendar.DAY_OF_MONTH);
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/LocalDateExtractYearMonthDayIntegerValues.java

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+package com.baeldung.datetime;
+
+import java.time.LocalDate;
+
+public class LocalDateExtractYearMonthDayIntegerValues {
+
+    int getYear(LocalDate localDate) {
+        return localDate.getYear();
+    }
+
+    int getMonth(LocalDate localDate) {
+        return localDate.getMonthValue();
+    }
+
+    int getDay(LocalDate localDate) {
+        return localDate.getDayOfMonth();
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/LocalDateTimeExtractYearMonthDayIntegerValues.java

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+package com.baeldung.datetime;
+
+import java.time.LocalDateTime;
+
+public class LocalDateTimeExtractYearMonthDayIntegerValues {
+
+    int getYear(LocalDateTime localDateTime) {
+        return localDateTime.getYear();
+    }
+
+    int getMonth(LocalDateTime localDateTime) {
+        return localDateTime.getMonthValue();
+    }
+
+    int getDay(LocalDateTime localDateTime) {
+        return localDateTime.getDayOfMonth();
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/OffsetDateTimeExtractYearMonthDayIntegerValues.java

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+package com.baeldung.datetime;
+
+import java.time.OffsetDateTime;
+
+public class OffsetDateTimeExtractYearMonthDayIntegerValues {
+
+    int getYear(OffsetDateTime offsetDateTime) {
+        return offsetDateTime.getYear();
+    }
+
+    int getMonth(OffsetDateTime offsetDateTime) {
+        return offsetDateTime.getMonthValue();
+    }
+
+    int getDay(OffsetDateTime offsetDateTime) {
+        return offsetDateTime.getDayOfMonth();
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/README.md

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+### Relevant Articles:

java-dates/src/main/java/com/baeldung/datetime/UseDateTimeFormatter.java

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+package com.baeldung.datetime;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.time.format.FormatStyle;
+import java.util.Locale;
+
+public class UseDateTimeFormatter {
+    public String formatAsIsoDate(LocalDateTime localDateTime) {
+        return localDateTime.format(DateTimeFormatter.ISO_DATE);
+    }
+
+    public String formatCustom(LocalDateTime localDateTime, String pattern) {
+        return localDateTime.format(DateTimeFormatter.ofPattern(pattern));
+    }
+
+    public String formatWithStyleAndLocale(LocalDateTime localDateTime, FormatStyle formatStyle, Locale locale) {
+        return localDateTime.format(DateTimeFormatter.ofLocalizedDateTime(formatStyle)
+            .withLocale(locale));
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/UseDuration.java

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+package com.baeldung.datetime;
+
+import java.time.Duration;
+import java.time.LocalTime;
+
+public class UseDuration {
+
+    public LocalTime modifyDates(LocalTime localTime, Duration duration) {
+        return localTime.plus(duration);
+    }
+
+    public Duration getDifferenceBetweenDates(LocalTime localTime1, LocalTime localTime2) {
+        return Duration.between(localTime1, localTime2);
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/UseLocalDate.java

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+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;
+
+class UseLocalDate {
+
+    LocalDate getLocalDateUsingFactoryOfMethod(int year, int month, int dayOfMonth) {
+        return LocalDate.of(year, month, dayOfMonth);
+    }
+
+    LocalDate getLocalDateUsingParseMethod(String representation) {
+        return LocalDate.parse(representation);
+    }
+
+    LocalDate getLocalDateFromClock() {
+        LocalDate localDate = LocalDate.now();
+        return localDate;
+    }
+
+    LocalDate getNextDay(LocalDate localDate) {
+        return localDate.plusDays(1);
+    }
+
+    LocalDate getPreviousDay(LocalDate localDate) {
+        return localDate.minus(1, ChronoUnit.DAYS);
+    }
+
+    DayOfWeek getDayOfWeek(LocalDate localDate) {
+        DayOfWeek day = localDate.getDayOfWeek();
+        return day;
+    }
+
+    LocalDate getFirstDayOfMonth() {
+        LocalDate firstDayOfMonth = LocalDate.now()
+            .with(TemporalAdjusters.firstDayOfMonth());
+        return firstDayOfMonth;
+    }
+
+    boolean isLeapYear(LocalDate localDate) {
+        return localDate.isLeapYear();
+    }
+
+    LocalDateTime getStartOfDay(LocalDate localDate) {
+        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;
+    }
+
+}

java-dates/src/main/java/com/baeldung/datetime/UseLocalDateTime.java

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+package com.baeldung.datetime;
+
+import java.time.LocalDateTime;
+import java.time.LocalTime;
+import java.time.ZoneOffset;
+import java.time.temporal.ChronoField;
+
+public class UseLocalDateTime {
+
+    public LocalDateTime getLocalDateTimeUsingParseMethod(String representation) {
+        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;
+    }
+
+    LocalDateTime ofEpochSecond(int epochSecond, ZoneOffset zoneOffset) {
+        return LocalDateTime.ofEpochSecond(epochSecond, 0, zoneOffset);
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/UseLocalTime.java

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+package com.baeldung.datetime;
+
+import java.time.LocalTime;
+import java.time.temporal.ChronoUnit;
+
+public class UseLocalTime {
+
+    LocalTime getLocalTimeUsingFactoryOfMethod(int hour, int min, int seconds) {
+        return LocalTime.of(hour, min, seconds);
+    }
+
+    LocalTime getLocalTimeUsingFactoryOfMethod(int hour, int min) {
+        return LocalTime.of(hour, min);
+    }
+
+    LocalTime getLocalTimeUsingParseMethod(String timeRepresentation) {
+        return LocalTime.parse(timeRepresentation);
+    }
+
+    private LocalTime getLocalTimeFromClock() {
+        return LocalTime.now();
+    }
+
+    LocalTime addAnHour(LocalTime localTime) {
+        return localTime.plus(1, ChronoUnit.HOURS);
+    }
+
+    int getHourFromLocalTime(LocalTime localTime) {
+        return localTime.getHour();
+    }
+
+    LocalTime getLocalTimeWithMinuteSetToValue(LocalTime localTime, int minute) {
+        return localTime.withMinute(minute);
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/UseOffsetDateTime.java

@@ -0,0 +1,11 @@
+package com.baeldung.datetime;
+
+import java.time.LocalDateTime;
+import java.time.OffsetDateTime;
+import java.time.ZoneOffset;
+
+public class UseOffsetDateTime {
+    public OffsetDateTime offsetOfLocalDateTimeAndOffset(LocalDateTime localDateTime, ZoneOffset offset) {
+        return OffsetDateTime.of(localDateTime, offset);
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/UsePeriod.java

@@ -0,0 +1,15 @@
+package com.baeldung.datetime;
+
+import java.time.LocalDate;
+import java.time.Period;
+
+class UsePeriod {
+
+    LocalDate modifyDates(LocalDate localDate, Period period) {
+        return localDate.plus(period);
+    }
+
+    Period getDifferenceBetweenDates(LocalDate localDate1, LocalDate localDate2) {
+        return Period.between(localDate1, localDate2);
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/UseToInstant.java

@@ -0,0 +1,17 @@
+package com.baeldung.datetime;
+
+import java.time.LocalDateTime;
+import java.time.ZoneId;
+import java.util.Calendar;
+import java.util.Date;
+
+public class UseToInstant {
+
+    public LocalDateTime convertDateToLocalDate(Date date) {
+        return LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault());
+    }
+
+    public LocalDateTime convertDateToLocalDate(Calendar calendar) {
+        return LocalDateTime.ofInstant(calendar.toInstant(), ZoneId.systemDefault());
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/UseZonedDateTime.java

@@ -0,0 +1,46 @@
+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 getZonedDateTimeUsingParseMethod(String parsableString) {
+        return ZonedDateTime.parse(parsableString);
+    }
+
+    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;
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/ZonedDateTimeExtractYearMonthDayIntegerValues.java

@@ -0,0 +1,18 @@
+package com.baeldung.datetime;
+
+import java.time.ZonedDateTime;
+
+public class ZonedDateTimeExtractYearMonthDayIntegerValues {
+
+    int getYear(ZonedDateTime zonedDateTime) {
+        return zonedDateTime.getYear();
+    }
+
+    int getMonth(ZonedDateTime zonedDateTime) {
+        return zonedDateTime.getMonthValue();
+    }
+
+    int getDay(ZonedDateTime zonedDateTime) {
+        return zonedDateTime.getDayOfMonth();
+    }
+}

java-dates/src/main/java/com/baeldung/datetime/modify/DateIncrementer.java

@@ -0,0 +1,63 @@
+package com.baeldung.datetime.modify;
+
+import org.apache.commons.lang3.time.DateUtils;
+import org.joda.time.DateTime;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.time.LocalDate;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.logging.Logger;
+
+public class DateIncrementer {
+    private static final Logger log = Logger.getLogger(DateIncrementer.class.getName());
+    private static final int INCREMENT_BY_IN_DAYS = 1;
+
+    public static String addOneDay(String date) {
+        return LocalDate
+          .parse(date)
+          .plusDays(INCREMENT_BY_IN_DAYS)
+          .toString();
+    }
+
+    public static String addOneDayJodaTime(String date) {
+        DateTime dateTime = new DateTime(date);
+        return dateTime
+          .plusDays(INCREMENT_BY_IN_DAYS)
+          .toString("yyyy-MM-dd");
+    }
+
+    public static String addOneDayCalendar(String date) throws ParseException {
+        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
+        Calendar c = Calendar.getInstance();
+        c.setTime(sdf.parse(date));
+        c.add(Calendar.DATE, 1);
+        return sdf.format(c.getTime());
+    }
+
+    public static String addOneDayApacheCommons(String date) throws ParseException {
+        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
+        Date incrementedDate = DateUtils.addDays(sdf.parse(date), 1);
+        return sdf.format(incrementedDate);
+    }
+
+    public static void main(String[] args) throws ParseException {
+        String date = LocalDate
+          .now()
+          .toString();
+        log.info("Current date = " + date);
+
+        String incrementedDateJava8 = DateIncrementer.addOneDay(date);
+        log.info("Date incremented by one day using (Java 8): " + incrementedDateJava8);
+
+        String incrementedDateJodaTime = DateIncrementer.addOneDayJodaTime(date);
+        log.info("Date incremented by one day using (Joda-Time): " + incrementedDateJodaTime);
+
+        String incrementedDateCalendar = addOneDayCalendar(date);
+        log.info("Date incremented by one day using (java.util.Calendar): " + incrementedDateCalendar);
+
+        String incrementedDateApacheCommons = addOneDayApacheCommons(date);
+        log.info("Date incremented by one day using (Apache Commons DateUtils): " + incrementedDateApacheCommons);
+    }
+}

java-dates/src/main/java/com/baeldung/gregorian/calendar/GregorianCalendarExample.java

@@ -0,0 +1,69 @@
+package com.baeldung.gregorian.calendar;
+
+import java.time.format.DateTimeFormatter;
+import java.util.Calendar;
+import java.util.Collections;
+import java.util.Date;
+import java.util.GregorianCalendar;
+import java.util.HashSet;
+import java.util.Locale;
+import java.util.Set;
+import java.util.TimeZone;
+
+import javax.xml.datatype.DatatypeConfigurationException;
+import javax.xml.datatype.DatatypeFactory;
+import javax.xml.datatype.XMLGregorianCalendar;
+
+public class GregorianCalendarExample {
+
+   
+    public Date setMonth(GregorianCalendar calendar, int amount) {
+        calendar.set(Calendar.MONTH, amount);
+        return calendar.getTime();
+    }
+
+   
+    public Date rollAdd(GregorianCalendar calendar, int amount) {
+        calendar.roll(GregorianCalendar.MONTH, amount);
+        return calendar.getTime();
+    }
+
+    public  boolean isLeapYearExample(int year) {
+        GregorianCalendar cal = (GregorianCalendar) GregorianCalendar.getInstance();
+        return cal.isLeapYear(year);
+    }
+
+
+
+    public Date subtractDays(GregorianCalendar calendar, int daysToSubtract) {
+        GregorianCalendar cal = calendar;
+        cal.add(Calendar.DATE, -daysToSubtract);
+        return cal.getTime();
+    }
+
+    public Date addDays(GregorianCalendar calendar, int daysToAdd) {
+        GregorianCalendar cal = calendar;
+        cal.add(Calendar.DATE, daysToAdd);
+        return cal.getTime();
+    }
+
+    public XMLGregorianCalendar toXMLGregorianCalendar(GregorianCalendar calendar) throws DatatypeConfigurationException {
+        DatatypeFactory datatypeFactory = DatatypeFactory.newInstance();
+        return datatypeFactory.newXMLGregorianCalendar(calendar);
+    }
+
+    public Date toDate(XMLGregorianCalendar calendar) {
+        return calendar.toGregorianCalendar()
+            .getTime();
+    }
+
+    public int compareDates(GregorianCalendar firstDate, GregorianCalendar secondDate) {
+        return firstDate.compareTo(secondDate);
+    }
+
+    public String formatDate(GregorianCalendar calendar) {
+        return calendar.toZonedDateTime()
+            .format(DateTimeFormatter.ofPattern("d MMM uuuu"));
+    }
+
+}

java-dates/src/main/java/com/baeldung/java9/time/TimeApi.java

@@ -0,0 +1,43 @@
+package com.baeldung.java9.time;
+
+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
+import java.util.ArrayList;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.GregorianCalendar;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+public class TimeApi {
+
+    public static List<Date> getDatesBetweenUsingJava7(Date startDate, Date endDate) {
+        List<Date> datesInRange = new ArrayList<Date>();
+        Calendar calendar = new GregorianCalendar();
+        calendar.setTime(startDate);
+
+        Calendar endCalendar = new GregorianCalendar();
+        endCalendar.setTime(endDate);
+
+        while (calendar.before(endCalendar)) {
+            Date result = calendar.getTime();
+            datesInRange.add(result);
+            calendar.add(Calendar.DATE, 1);
+        }
+        return datesInRange;
+    }
+
+    public static List<LocalDate> getDatesBetweenUsingJava8(LocalDate startDate, LocalDate endDate) {
+        long numOfDaysBetween = ChronoUnit.DAYS.between(startDate, endDate);
+        return IntStream.iterate(0, i -> i + 1)
+                 .limit(numOfDaysBetween)
+                 .mapToObj(i -> startDate.plusDays(i))
+                 .collect(Collectors.toList());
+    }
+
+    public static List<LocalDate> getDatesBetweenUsingJava9(LocalDate startDate, LocalDate endDate) {
+        return startDate.datesUntil(endDate).collect(Collectors.toList());
+    }
+
+}

java-dates/src/main/java/com/baeldung/temporaladjuster/CustomTemporalAdjuster.java

@@ -0,0 +1,22 @@
+package com.baeldung.temporaladjuster;
+
+import java.time.DayOfWeek;
+import java.time.temporal.ChronoField;
+import java.time.temporal.ChronoUnit;
+import java.time.temporal.Temporal;
+import java.time.temporal.TemporalAdjuster;
+
+public class CustomTemporalAdjuster implements TemporalAdjuster {
+
+    @Override
+    public Temporal adjustInto(Temporal temporal) {
+        switch (DayOfWeek.of(temporal.get(ChronoField.DAY_OF_WEEK))) {
+        case FRIDAY:
+            return temporal.plus(3, ChronoUnit.DAYS);
+        case SATURDAY:
+            return temporal.plus(2, ChronoUnit.DAYS);
+        default:
+            return temporal.plus(1, ChronoUnit.DAYS);
+        }
+    }
+}