The setFirstDayOfWeek(int day_val) method in Calendar class is used to set the first day of the week using the day_val in this Calendar.
Syntax:
public void set(int day_val)
Parameters: The method takes one parameter day_val of integer type and refers to the first day of the week.
Return Value: The method does not return any value.
Below programs illustrate the working of setFirstDayOfWeek() Method of Calendar class:
Example 1:
// Java code to illustrate// setFirstDayOfWeek() method  import java.util.*;  public class Calendar_Demo {    public static void main(String args[])    {          // Creating calendar object        Calendar calndr = Calendar.getInstance();          // Displaying first day of the week        int first_day = calndr.getFirstDayOfWeek();        System.out.println("The Current"                           + " First day of the week: "                           + first_day);          // Changing the first day of week        calndr.setFirstDayOfWeek(Calendar.THURSDAY);          // Displaying the alternate day        first_day = calndr.getFirstDayOfWeek();        System.out.println("The new first"                           + " day of the week: "                           + first_day);    }} |
Output:
The Current First day of the week: 1 The new first day of the week: 5
Example 2:
// Java code to illustrate// setFirstDayOfWeek() method  import java.util.*;public class Calendar_Demo {    public static void main(String args[])    {          // Creating calendar object        Calendar calndr            = new GregorianCalendar(2018, 6, 10);          // Displaying first day of the week        int first_day = calndr.getFirstDayOfWeek();        System.out.println("The"                           + " First day of the week: "                           + first_day);          // Changing the first day of week        calndr.setFirstDayOfWeek(Calendar.MONDAY);          // Displaying the alternate day        first_day = calndr.getFirstDayOfWeek();        System.out.println("The new first"                           + " day of the week: "                           + first_day);    }} |
Output:
The First day of the week: 1 The new first day of the week: 2
Reference: https://docs.oracle.com/javase/8/docs/api/java/util/Calendar.html#setFirstDayOfWeek-int-
