ZonedDateTime minusDays() method in Java with Examples

minusDays() method of a ZonedDateTime class used to subtract the number of specified days from this ZonedDateTime and return a copy of ZonedDateTime.This method subtracts no of days passed as a parameter from 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 minusDays(long days)

Parameters: This method accepts a single parameter days which represents the days to subtract, It can be negative.

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

Exception: This method throws DateTimeException if the result exceeds the supported date range.

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

// Java program to demonstrate
// ZonedDateTime.minusDays() 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"
                           + " subtracting days: "
                           + zoneddatetime);

        // subtract 13 days
        ZonedDateTime returnvalue
            = zoneddatetime.minusDays(13);

        // print result
        System.out.println("ZonedDateTime after "
                           + " subtracting 13 days: "
                           + returnvalue);
    }
}

Output:

ZonedDateTime before subtracting days: 2018-12-06T19:21:12.123+05:30[Asia/Calcutta]
ZonedDateTime after subtracting 13 days: 2018-11-23T19:21:12.123+05:30[Asia/Calcutta]

Program 2:

// Java program to demonstrate
// ZonedDateTime.minusDays() 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"
                           + " subtracting days: "
                           + zoneddatetime);

        // subtract 22 days
        ZonedDateTime returnvalue
            = zoneddatetime.minusDays(20);

        // print result
        System.out.println("ZonedDateTime after "
                           + " subtracting 24 days: "
                           + returnvalue);
    }
}

Output:

ZonedDateTime before subtracting days: 2018-10-25T23:12:31.123+02:00[Europe/Paris]
ZonedDateTime after subtracting 24 days: 2018-10-05T23:12:31.123+02:00[Europe/Paris]

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