ZonedDateTime plusDays() method in Java with Examples

Last Updated : 07 May, 2019

The plusDays() method of ZonedDateTime class in Java is used to add the number of specified days in this ZonedDateTime instance and return a copy of ZonedDateTime. This method adds no of days passed as a parameter to the local date-time and then it 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 plusDays(long days)

Parameters: This method accepts a single parameter days which represents the days to add, It can be negative. Return value: This method returns a ZonedDateTime based on this date-time with the days added, not null. Exception: This method throws DateTimeException if the result exceeds the supported date range. Below programs illustrate the plusDays() method: Program 1:

Java

// Java program to demonstrate
// ZonedDateTime.plusDays() 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"
                           + " adding days: " + zoneddatetime);

        // add 3 days
        ZonedDateTime returnvalue
            = zoneddatetime.plusDays(3);

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

Output:

ZonedDateTime before adding days: 2018-12-06T19:21:12.123+05:30[Asia/Calcutta]
ZonedDateTime after  adding days: 2018-12-09T19:21:12.123+05:30[Asia/Calcutta]

Program 2:

Java

// Java program to demonstrate
// ZonedDateTime.plusDays() 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"
                           + " adding days: " + zoneddatetime);

        // add 20 days
        ZonedDateTime returnvalue
            = zoneddatetime.plusDays(20);

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

Output:

ZonedDateTime before adding days: 2018-10-25T23:12:31.123+02:00[Europe/Paris]
ZonedDateTime after  adding days: 2018-11-14T23:12:31.123+01:00[Europe/Paris]

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