(Use the GregorianCalendar class) Java API has the GregorianCalendar class in the java.util package, which you can use to obtain the year, month, and day of a date. The no-arg constructor constructs an instance for the current date, and the methods get(GregorianCalendar.YEAR), get(GregorianCalendar. MONTH), and get(GregorianCalendar.DAY_OF_MONTH) return the year, month, and day. Write a program to perform two tasks: 1.Display the current year, month, and day. 2.The GregorianCalendar class has the setTimeInMillis(long), which can be used to set a specified elapsed time since January 1, 1970. Set the value to 1234567898765L and display the year, month, and day.

Here is the Java program that performs the two tasks as described:

import java.util.GregorianCalendar;

public class GregorianCalendarDemo {
    public static void main(String[] args) {
        // Display the current year, month, and day
        GregorianCalendar calendar = new GregorianCalendar();
        int year = calendar.get(GregorianCalendar.YEAR);
        int month = calendar.get(GregorianCalendar.MONTH) + 1; // add 1 to get the actual month value
        int day = calendar.get(GregorianCalendar.DAY_OF_MONTH);
        System.out.println("Current date: " + year + "-" + month + "-" + day);

        // Set the elapsed time to 1234567898765L and display the year, month, and day
        calendar.setTimeInMillis(1234567898765L);
        year = calendar.get(GregorianCalendar.YEAR);
        month = calendar.get(GregorianCalendar.MONTH) + 1; // add 1 to get the actual month value
        day = calendar.get(GregorianCalendar.DAY_OF_MONTH);
        System.out.println("Elapsed time since January 1, 1970: " + year + "-" + month + "-" + day);
    }
}

The output of this program will be:

Current date: 2021-4-21
Elapsed time since January 1, 1970: 2009-2-13

Note that the current date will depend on your system clock, but the elapsed time since January 1, 1970 will always be the same.