Java : MonthDay with Examples

MonthDay (Java SE 21 & JDK 21) with Examples.
You will find code examples on most MonthDay methods.

Summary

A month-day in the ISO-8601 calendar system, such as --12-03.

Class diagram

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

System.out.println(monthDay.getMonth()); // APRIL
System.out.println(monthDay.getMonthValue()); // 4
System.out.println(monthDay.getDayOfMonth()); // 15

Methods

Temporal adjustInto (Temporal temporal)

Adjusts the specified temporal object to have this month-day.

final var monthDay = MonthDay.of(Month.DECEMBER, 15);
System.out.println(monthDay); // --12-15

final var date = LocalDate.of(2100, 2, 3);
System.out.println(date); // 2100-02-03

final var ret = monthDay.adjustInto(date);
System.out.println(ret); // 2100-12-15

LocalDate atYear (int year)

Combines this month-day with a year to create a LocalDate.

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

System.out.println(monthDay.atYear(2100)); // 2100-04-15
System.out.println(monthDay.atYear(1800)); // 1800-04-15

int compareTo (MonthDay other)

Compares this month-day to another month-day.

final var monthDay1 = MonthDay.of(Month.JANUARY, 15);
final var monthDay2 = MonthDay.of(Month.JANUARY, 15);

System.out.println(monthDay1); // --01-15
System.out.println(monthDay2); // --01-15

System.out.println(monthDay1.compareTo(monthDay2)); // 0
System.out.println(monthDay2.compareTo(monthDay1)); // 0

final var monthDay1 = MonthDay.of(Month.JANUARY, 15);
final var monthDay2 = MonthDay.of(Month.FEBRUARY, 15);

System.out.println(monthDay1); // --01-15
System.out.println(monthDay2); // --02-15

System.out.println(monthDay1.compareTo(monthDay2)); // -1
System.out.println(monthDay2.compareTo(monthDay1)); // 1

final var monthDay1 = MonthDay.of(Month.APRIL, 2);
final var monthDay2 = MonthDay.of(Month.APRIL, 1);

System.out.println(monthDay1); // --04-02
System.out.println(monthDay2); // --04-01

System.out.println(monthDay1.compareTo(monthDay2)); // 1
System.out.println(monthDay2.compareTo(monthDay1)); // -1

boolean equals (Object obj)

Checks if this month-day is equal to another month-day.

final var monthDay1 = MonthDay.of(Month.JANUARY, 15);
final var monthDay2 = MonthDay.of(Month.JANUARY, 15);

System.out.println(monthDay1); // --01-15
System.out.println(monthDay2); // --01-15

System.out.println(monthDay1.equals(monthDay2)); // true
System.out.println(monthDay2.equals(monthDay1)); // true

final var monthDay1 = MonthDay.of(Month.JANUARY, 15);
final var monthDay2 = MonthDay.of(Month.FEBRUARY, 15);

System.out.println(monthDay1); // --01-15
System.out.println(monthDay2); // --02-15

System.out.println(monthDay1.equals(monthDay2)); // false
System.out.println(monthDay2.equals(monthDay1)); // false

final var monthDay1 = MonthDay.of(Month.APRIL, 2);
final var monthDay2 = MonthDay.of(Month.APRIL, 1);

System.out.println(monthDay1); // --04-02
System.out.println(monthDay2); // --04-01

System.out.println(monthDay1.equals(monthDay2)); // false
System.out.println(monthDay2.equals(monthDay1)); // false

String format (DateTimeFormatter formatter)

Formats this month-day using the specified formatter.

final var monthDay = MonthDay.of(Month.APRIL, 1);
System.out.println(monthDay); // --04-01

final var ret1 = monthDay.format(DateTimeFormatter.ofPattern("MM-dd"));
System.out.println(ret1); // 04-01

final var ret2 = monthDay.format(DateTimeFormatter.ofPattern("M-d"));
System.out.println(ret2); // 4-1

static MonthDay from (TemporalAccessor temporal)

Obtains an instance of MonthDay from a temporal object.

final var date = LocalDate.of(2100, 2, 3);
System.out.println(date); // 2100-02-03

final var ret = MonthDay.from(date);
System.out.println(ret); // --02-03

final var dateTime = LocalDateTime.of(1999, 12, 31, 7, 30);
System.out.println(dateTime); // 1999-12-31T07:30

final var ret = MonthDay.from(dateTime);
System.out.println(ret); // --12-31

int get (TemporalField field)

Gets the value of the specified field from this month-day as an int.

final var monthDay = MonthDay.of(Month.JANUARY, 15);
System.out.println(monthDay); // --01-15

System.out.println(monthDay.get(ChronoField.MONTH_OF_YEAR)); // 1
System.out.println(monthDay.get(ChronoField.DAY_OF_MONTH)); // 15

final var monthDay = MonthDay.of(Month.DECEMBER, 31);
System.out.println(monthDay); // --12-31

System.out.println(monthDay.get(ChronoField.MONTH_OF_YEAR)); // 12
System.out.println(monthDay.get(ChronoField.DAY_OF_MONTH)); // 31

int getDayOfMonth ()

Gets the day-of-month field.

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

System.out.println(monthDay.getMonth()); // APRIL
System.out.println(monthDay.getMonthValue()); // 4
System.out.println(monthDay.getDayOfMonth()); // 15

long getLong (TemporalField field)

Gets the value of the specified field from this month-day as a long.

final var monthDay = MonthDay.of(Month.JANUARY, 15);
System.out.println(monthDay); // --01-15

System.out.println(monthDay.getLong(ChronoField.MONTH_OF_YEAR)); // 1
System.out.println(monthDay.getLong(ChronoField.DAY_OF_MONTH)); // 15

final var monthDay = MonthDay.of(Month.DECEMBER, 31);
System.out.println(monthDay); // --12-31

System.out.println(monthDay.getLong(ChronoField.MONTH_OF_YEAR)); // 12
System.out.println(monthDay.getLong(ChronoField.DAY_OF_MONTH)); // 31

Month getMonth ()

Gets the month-of-year field using the Month enum.

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

System.out.println(monthDay.getMonth()); // APRIL
System.out.println(monthDay.getMonthValue()); // 4
System.out.println(monthDay.getDayOfMonth()); // 15

int getMonthValue ()

Gets the month-of-year field from 1 to 12.

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

System.out.println(monthDay.getMonth()); // APRIL
System.out.println(monthDay.getMonthValue()); // 4
System.out.println(monthDay.getDayOfMonth()); // 15

int hashCode ()

A hash code for this month-day.

final var monthDay = MonthDay.of(Month.JANUARY, 15);
System.out.println(monthDay); // --01-15
System.out.println(monthDay.hashCode()); // 79

final var monthDay = MonthDay.of(Month.DECEMBER, 31);
System.out.println(monthDay); // --12-31
System.out.println(monthDay.hashCode()); // 799

boolean isAfter (MonthDay other)

Checks if this month-day is after the specified month-day.

final var monthDay = MonthDay.of(Month.FEBRUARY, 1);
System.out.println(monthDay); // --02-01

final var monthDay2 = MonthDay.of(Month.JANUARY, 31);
final var monthDay3 = MonthDay.of(Month.FEBRUARY, 1);
final var monthDay4 = MonthDay.of(Month.FEBRUARY, 2);

System.out.println(monthDay2); // --01-31
System.out.println(monthDay3); // --02-01
System.out.println(monthDay4); // --02-02

System.out.println(monthDay.isAfter(monthDay2)); // true
System.out.println(monthDay.isAfter(monthDay3)); // false
System.out.println(monthDay.isAfter(monthDay4)); // false

boolean isBefore (MonthDay other)

Checks if this month-day is before the specified month-day.

final var monthDay = MonthDay.of(Month.FEBRUARY, 1);
System.out.println(monthDay); // --02-01

final var monthDay2 = MonthDay.of(Month.JANUARY, 31);
final var monthDay3 = MonthDay.of(Month.FEBRUARY, 1);
final var monthDay4 = MonthDay.of(Month.FEBRUARY, 2);

System.out.println(monthDay2); // --01-31
System.out.println(monthDay3); // --02-01
System.out.println(monthDay4); // --02-02

System.out.println(monthDay.isBefore(monthDay2)); // true
System.out.println(monthDay.isBefore(monthDay3)); // false
System.out.println(monthDay.isBefore(monthDay4)); // false

boolean isSupported (TemporalField field)

Checks if the specified field is supported.

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

System.out.println(monthDay.isSupported(ChronoField.MONTH_OF_YEAR)); // true
System.out.println(monthDay.isSupported(ChronoField.DAY_OF_MONTH)); // true

System.out.println(monthDay.isSupported(ChronoField.YEAR)); // false

boolean isValidYear (int year)

Checks if the year is valid for this month-day.

final var monthDay = MonthDay.of(Month.FEBRUARY, 29);
System.out.println(monthDay); // --02-29

System.out.println(Year.isLeap(2103)); // false
System.out.println(monthDay.isValidYear(2103)); // false

System.out.println(Year.isLeap(2104)); // true
System.out.println(monthDay.isValidYear(2104)); // true

static MonthDay now ()

Obtains the current month-day from the system clock in the default time-zone.

final var now = MonthDay.now();
System.out.println(now); // --10-19

static MonthDay now (Clock clock)

Obtains the current month-day from the specified clock.

// A clock advanced 5 days.
final var clock = Clock.offset(Clock.systemDefaultZone(), Duration.ofDays(5));

System.out.println(MonthDay.now()); // --10-19
System.out.println(MonthDay.now(clock)); // --10-24

static MonthDay now (ZoneId zone)

Obtains the current month-day from the system clock in the specified time-zone.

final var zone = ZoneOffset.UTC;
System.out.println(zone); // Z

final var now = MonthDay.now(zone);
System.out.println(now); // --10-19

static MonthDay of (int month, int dayOfMonth)

Obtains an instance of MonthDay.

final var monthDay = MonthDay.of(1, 2);
System.out.println(monthDay.getMonth()); // JANUARY
System.out.println(monthDay.getMonthValue()); // 1
System.out.println(monthDay.getDayOfMonth()); // 2

final var monthDay = MonthDay.of(12, 15);
System.out.println(monthDay.getMonth()); // DECEMBER
System.out.println(monthDay.getMonthValue()); // 12
System.out.println(monthDay.getDayOfMonth()); // 15

static MonthDay of (Month month, int dayOfMonth)

Obtains an instance of MonthDay.

final var monthDay = MonthDay.of(Month.JANUARY, 2);
System.out.println(monthDay.getMonth()); // JANUARY
System.out.println(monthDay.getMonthValue()); // 1
System.out.println(monthDay.getDayOfMonth()); // 2

final var monthDay = MonthDay.of(Month.DECEMBER, 15);
System.out.println(monthDay.getMonth()); // DECEMBER
System.out.println(monthDay.getMonthValue()); // 12
System.out.println(monthDay.getDayOfMonth()); // 15

static MonthDay parse (CharSequence text)

Obtains an instance of MonthDay from a text string such as --12-03.

final var monthDay1 = MonthDay.parse("--04-05");
System.out.println(monthDay1); // --04-05

final var monthDay2 = MonthDay.parse("--12-31");
System.out.println(monthDay2); // --12-31

static MonthDay parse (CharSequence text, DateTimeFormatter formatter)

Obtains an instance of MonthDay from a text string using a specific formatter.

final var monthDay1 = MonthDay.parse(
        "04-05", DateTimeFormatter.ofPattern("MM-dd"));
System.out.println(monthDay1); // --04-05

final var monthDay2 = MonthDay.parse(
        "8-1", DateTimeFormatter.ofPattern("M-d"));
System.out.println(monthDay2); // --08-01

<R> R query (TemporalQuery<R> query)

Queries this month-day using the specified query.

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

final var ret = monthDay.query(TemporalQueries.chronology());
System.out.println(ret); // ISO

ValueRange range (TemporalField field)

Gets the range of valid values for the specified field.

final var monthDay = MonthDay.of(Month.JANUARY, 1);
System.out.println(monthDay); // --01-01

System.out.println(monthDay.range(ChronoField.MONTH_OF_YEAR)); // 1 - 12
System.out.println(monthDay.range(ChronoField.DAY_OF_MONTH)); // 1 - 31

final var monthDay = MonthDay.of(Month.FEBRUARY, 1);
System.out.println(monthDay); // --02-01

System.out.println(monthDay.range(ChronoField.MONTH_OF_YEAR)); // 1 - 12
System.out.println(monthDay.range(ChronoField.DAY_OF_MONTH)); // 1 - 28/29

String toString ()

Outputs this month-day as a String, such as --12-03.

final var monthDay = MonthDay.of(Month.JANUARY, 15);
final var str = monthDay.toString();
System.out.println(str); // --01-15

final var monthDay = MonthDay.of(Month.DECEMBER, 31);
final var str = monthDay.toString();
System.out.println(str); // --12-31

MonthDay with (Month month)

Returns a copy of this MonthDay with the month-of-year altered.

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

final var ret1 = monthDay.with(Month.DECEMBER);
System.out.println(ret1); // --12-15

final var ret2 = monthDay.withDayOfMonth(30);
System.out.println(ret2); // --04-30

final var ret3 = monthDay.withMonth(1);
System.out.println(ret3); // --01-15

MonthDay withDayOfMonth (int dayOfMonth)

Returns a copy of this MonthDay with the day-of-month altered.

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

final var ret1 = monthDay.with(Month.DECEMBER);
System.out.println(ret1); // --12-15

final var ret2 = monthDay.withDayOfMonth(30);
System.out.println(ret2); // --04-30

final var ret3 = monthDay.withMonth(1);
System.out.println(ret3); // --01-15

MonthDay withMonth (int month)

Returns a copy of this MonthDay with the month-of-year altered.

final var monthDay = MonthDay.of(Month.APRIL, 15);
System.out.println(monthDay); // --04-15

final var ret1 = monthDay.with(Month.DECEMBER);
System.out.println(ret1); // --12-15

final var ret2 = monthDay.withDayOfMonth(30);
System.out.println(ret2); // --04-30

final var ret3 = monthDay.withMonth(1);
System.out.println(ret3); // --01-15

API Examples
- Calendar
- ChronoLocalDate
- ChronoLocalDateTime
- ChronoZonedDateTime
- Clock
- Date
- DateTimeException
- DateTimeParseException
- DayOfWeek
- Duration
- Era
  - IsoEra
  - JapaneseEra
- Instant
- InstantSource
- JapaneseDate
- LocalDate
- LocalDateTime
- LocalTime
- Month
- OffsetDateTime
- OffsetTime
- Period
- Temporal
- TemporalAccessor
- TemporalAdjuster
- TemporalAdjusters
- TimeZone
- Year
- YearMonth
- ZonedDateTime
- ZoneId
- ZoneOffset

Java : MonthDay with Examples

Summary

Methods

Temporal adjustInto (Temporal temporal)

LocalDate atYear (int year)

int compareTo (MonthDay other)

boolean equals (Object obj)

String format (DateTimeFormatter formatter)

static MonthDay from (TemporalAccessor temporal)

int get (TemporalField field)

int getDayOfMonth ()

long getLong (TemporalField field)

Month getMonth ()

int getMonthValue ()

int hashCode ()

boolean isAfter (MonthDay other)

boolean isBefore (MonthDay other)

boolean isSupported (TemporalField field)

boolean isValidYear (int year)

static MonthDay now ()

static MonthDay now (Clock clock)

static MonthDay now (ZoneId zone)

static MonthDay of (int month, int dayOfMonth)

static MonthDay of (Month month, int dayOfMonth)

static MonthDay parse (CharSequence text)

static MonthDay parse (CharSequence text, DateTimeFormatter formatter)

<R> R query (TemporalQuery<R> query)

ValueRange range (TemporalField field)

String toString ()

MonthDay with (Month month)

MonthDay withDayOfMonth (int dayOfMonth)

MonthDay withMonth (int month)

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