IsoChronology date(int, int, int) method in Java with Example

The date() method of java.time.chrono.IsoChronology class is used get the local date according to ISO calendar system for the given year, month and day.

Syntax:

public LocalDate date(int prolepticYear,
                      int month,
                      int dayOfMonth)

Parameter: This method takes the following arguments as parameter.  

• prolepticYear: integer proleptic year for the year field of ISO
• month: integer month for the month field of ISO
• day: integer day for the day field of ISO

Return Value: This method returns the local date according to Iso calendar system for the given year, month and day.
Exception: This method throws DateTimeException if the given field of day, month and year are unable to form a structured date.
Below are the examples to illustrate the date() method:
Example 1:

Java

// Java program to demonstrate
// date() method

import java.util.*;
import java.io.*;
import java.time.*;
import java.time.chrono.*;

public class GFG {
    public static void main(String[] argv)
    {
        try {
            // creating and initializing LocalDate Object
            LocalDate lodate = LocalDate.now();

            // getting IsoChronology used in LocalDate
            IsoChronology crono = lodate.getChronology();

            // getting LocalDate for the
            // given date, month and year field
            // by using date() method
            LocalDate date = crono.date(1440, 05, 24);

            // display the result
            System.out.println("LocalDate is: " + date);
        }
        catch (DateTimeException e) {
            System.out.println("passed parameter can "
                               + "not form a date");
            System.out.println("Exception thrown: " + e);
        }
    }
}

Output:

LocalDate is: 1440-05-24

Example 2:

Java

// Java program to demonstrate
// date() method

import java.util.*;
import java.io.*;
import java.time.*;
import java.time.chrono.*;

public class GFG {
    public static void main(String[] argv)
    {
        try {
            // creating and initializing LocalDate Object
            LocalDate lodate = LocalDate.now();

            // getting IsoChronology used in LocalDate
            IsoChronology crono = lodate.getChronology();

            // getting LocalDate for the
            // given date, month and year field
            // by using date() method
            LocalDate date = crono.date(2020, 05, 34);

            // display the result
            System.out.println("LocalDate is: " + date);
        }
        catch (DateTimeException e) {
            System.out.println("passed parameter can "
                               + "not form a date");
            System.out.println("Exception thrown: " + e);
        }
    }
}

Output

passed parameter can not form a date
Exception thrown: java.time.DateTimeException: Invalid value for DayOfMonth (valid values 1 - 28/31): 34

Reference: https://docs.oracle.com/javase/9/docs/api/java/time/chrono/IsoChronology.html#date-int-int-int-