Java MonthDay Class explained with examples

The MonthDay class represents the date as the combination of Month and Day such as --11-25. This class only represents the Month and day, it doesn’t represents the year, time or time-zone.

Java MonthDay class:

public final class MonthDay extends Object
implements TemporalAccessor, TemporalAdjuster, Comparable<MonthDay>, Serializable

Java MonthDay class – Method Summary

Method	Description
LocalDate atYear(int year)	It combines this month-day with the specified year to create an instance of LocalDate.
int compareTo(MonthDay other)	It compares this month-day to another month-day and returns an int value. The negative value indicates that this month-day is less than the other month-day and the positive value indicates that this month-day is greater than the other month-day.
boolean equals(Object obj)	Checks if this month-day is equal to the other specified month-day.
int getMonthValue()	Gets month value from this month-day. The value ranges from 1 to 12 where 1 represents “January” and 12 represents “December”.
boolean isAfter(MonthDay other)	Checks if this month-day is after the another month-day.
boolean isBefore(MonthDay other)	Checks if this month-day is before the another month-day.
static MonthDay now()	It returns the current month-day from the system in default time-zone.
MonthDay with(Month month)	It returns the copy of the month-day after altering the month with the specified value.
MonthDay withDayOfMonth(int dayOfMonth)	It returns the copy of this month-day after altering the day of the month value with the specified value.

Java MonthDay class Example – now() and of() methods

In the following example, we are seeing the usage of now() and of() methods.

import java.time.*;
public class JavaExample {
    public static void main(String[] args) {
        //now() method : returns current month & day
        MonthDay monthDay = MonthDay.now();
        System.out.println("Current Month & Day: "+monthDay);

        //of method() : returns month & day with the specified value
        MonthDay monthDay2 = MonthDay.of(12, 25);
        System.out.println("Specified Month & Day:"+monthDay2);
    }
}

Output:

Current Month & Day: --06-12
Specified Month & Day:--12-25

Java MonthDay class Example – range() & isValidYear() methods

Here we will learn how to use range() and isValidYear() methods. The range() method is used to find the range of the month & days. The isValidYear() method checks whether the specified year is valid or not.

import java.time.*;
import java.time.temporal.*;
public class JavaExample {
    public static void main(String[] args) {
        //range() method
        MonthDay month = MonthDay.now();
        ValueRange range1 = month.range(ChronoField.MONTH_OF_YEAR);
        System.out.println("Month Range: "+range1);
        ValueRange range2 = month.range(ChronoField.DAY_OF_MONTH);
        System.out.println("Day range: "+range2);

        //isValidYear() method
        boolean flag = month.isValidYear(2022);
        System.out.println("Is 2022 valid year?: "+flag);
    }
}

Output:

Month Range: 1 - 12
Day range: 1 - 30
Is 2022 valid year?: true

Java MonthDay class – get() method example

The get() method is used to get the specified field from this month-day. In this example, we fetched the MONTH_OF_YEAR and DAY_OF_MONTH value from this month-day.

import java.time.*;
import java.time.temporal.*;
public class JavaExample{
    public static void main(String[] args) {
        MonthDay monthDay = MonthDay.now();
        System.out.println("Current date: "+monthDay);
        long m = monthDay.get(ChronoField.MONTH_OF_YEAR);
        System.out.println("Month of year: "+m);
        long d = monthDay.get(ChronoField.DAY_OF_MONTH);
        System.out.println("Day of month: "+d);
    }
}

Output:

Current date: --06-12
Month of year: 6
Day of month: 12

The other possible values that you can find using get() method are:

Java MonthDay – isBefore(), isAfter() & withMonth() methods example

Methods isBefore() and isAfter() are used for comparison, they just returns true or false based on the comparison. If this month-day is before the specified month-day then isBefore() will return true else it returns false.

Method withMonth() alters the month field of this month-day with the specified value. Other with methods are with(Month month) & withDayOfMonth(int dayOfMonth).

import java.time.*;
public class JavaExample{
    public static void main(String[] args) {
        MonthDay monthDay = MonthDay.now();
        System.out.println("Current date: "+monthDay);
        MonthDay monthDay2 = monthDay.withMonth(2);
        System.out.println("Altered Date: "+monthDay2);

        //Is current date before altered date?
        System.out.println(monthDay.isBefore(monthDay2));

        //Is current date after altered date?
        System.out.println(monthDay.isAfter(monthDay2));
    }
}

Output:

Current date: --06-12
Altered Date: --02-12
false
true