ZonedDateTime withMonth() method in Java with Examples

withMonth() method of a ZonedDateTime class used to alter month-of-year in this ZonedDateTime and return a copy of ZonedDateTime after this operation.This method operates on the local time-line, changing the month of the local date-time and after this operation local date-time is converted back to a ZonedDateTime, using the zone ID to obtain the offset. When converting back to ZonedDateTime, if the local date-time is in an overlap, then the offset will be retained if possible, otherwise, the earlier offset will be used. This instance is immutable and unaffected by this method call.

Syntax:

public ZonedDateTime withMonth(int month)

Parameters: This method accepts a single parameter month which represents the month-of-year to set in the result, from 1 (January) to 12 (December).

Return value: This method returns a ZonedDateTime based on this date-time with the requested month.

Exception: This method throws DateTimeException if the month value is invalid.

Below programs illustrate the withMonth() method:
Program 1:

// Java program to demonstrate
// ZonedDateTime.withMonth() method

import java.time.*;

public class GFG {
    public static void main(String[] args)
    {

        // create a ZonedDateTime object
        ZonedDateTime zoneddatetime
            = ZonedDateTime.parse(
                "2018-12-06T19:21:12.123+05:30[Asia/Calcutta]");

        // print instance
        System.out.println("ZonedDateTime before"
                           + " alter month: "
                           + zoneddatetime);

        // alter month to 5(May)
        ZonedDateTime returnvalue
            = zoneddatetime.withMonth(5);

        // print result
        System.out.println("ZonedDateTime after "
                           + "alter month: "
                           + returnvalue);
    }
}

Output:

ZonedDateTime before alter month: 2018-12-06T19:21:12.123+05:30[Asia/Calcutta]
ZonedDateTime after alter month: 2018-05-06T19:21:12.123+05:30[Asia/Calcutta]

Program 2:

// Java program to demonstrate
// ZonedDateTime.withMonth() method

import java.time.*;

public class GFG {
    public static void main(String[] args)
    {

        // create a ZonedDateTime object
        ZonedDateTime zoneddatetime
            = ZonedDateTime.parse(
                "2018-10-25T23:12:31.123+02:00[Europe/Paris]");

        // print instance
        System.out.println("ZonedDateTime before"
                           + " alter month: "
                           + zoneddatetime);

        // alter month to 12(december)
        ZonedDateTime returnvalue
            = zoneddatetime.withMonth(12);

        // print result
        System.out.println("ZonedDateTime after "
                           + "alter month: "
                           + returnvalue);
    }
}

Output:

ZonedDateTime before alter month: 2018-10-25T23:12:31.123+02:00[Europe/Paris]
ZonedDateTime after alter month: 2018-12-25T23:12:31.123+01:00[Europe/Paris]

Reference: https://docs.oracle.com/javase/10/docs/api/java/time/ZonedDateTime.html#withMonth(int)