public final void clear()

// Java Code to illustrate clear() Method
  
import java.util.Calendar;
  
public class CalendarClassDemo {
    public static void main(String args[])
    {
        // Creating a calendar object
        Calendar calndr = Calendar.getInstance();
  
        // Displaying the Current Date
        System.out.println("Current Date&Time: "
                           + calndr.getTime());
  
        // Clear method for undefining the values
        // of the calendar
        calndr.clear();
  
        // Displaying the final result
        System.out.println("After clear method: "
                           + calndr.getTime());
    }
}

Current Date&Time: Tue Feb 12 13:01:42 UTC 2019
After clear method: Thu Jan 01 00:00:00 UTC 1970

// Java Code to illustrate clone() Method
  
import java.util.*;
  
public class CalendarClassDemo {
    public static void main(String args[])
    {
        // Creating a calendar object
        Calendar calndr1 = new GregorianCalendar(2018, 12, 2);
  
        // Displaying current calendar
        System.out.println("Original calendar: "
                           + calndr1.getTime());
  
        // Clear method for undefining the values
        // of the calendar
        calndr1.clear();
  
        // Displaying the final result
        System.out.println("After clear method: "
                           + calndr1.getTime());
    }
}

Original calendar: Wed Jan 02 00:00:00 UTC 2019
After clear method: Thu Jan 01 00:00:00 UTC 1970