How to Change the Calendar Type in the Regional Settings Using CSOM in SharePoint 2013 Online

In this blog you will see how to change the Calendar Type in the regional settings using CSOM in SharePoint 2013 Online.

Code Snippet: 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Security;
using System.Text;
using System.Threading.Tasks;
using Microsoft.SharePoint.Client;

namespace CSOMOffice365
{
    class Program
    {
        static void Main(string[] args)
        {

            string userName = "[email protected]";

            Console.WriteLine("Enter your password.");
            SecureString password = GetPassword();

            // ClienContext - Get the context for the SharePoint Online Site
            // SharePoint site URL - https://c986.sharepoint.com

            using (var clientContext = new ClientContext("https://c986.sharepoint.com"))
            {
                // SharePoint Online Credentials
                clientContext.Credentials = new SharePointOnlineCredentials(userName, password);

                // Get the SharePoint web
                Web web = clientContext.Web;

                // Regional Settings: Change the calendar type and alternate calendar type
                // Reference: https://msdn.microsoft.com/en-us/library/microsoft.sharepoint.client.regionalsettings.calendartype.aspx
                RegionalSettings regSet = web.RegionalSettings;

                // Change the calendar type to 5 - Korean Tangun Era
                regSet.CalendarType = 5;
                regSet.AlternateCalendarType = 5;

                // Update the regional settings
                regSet.Update();
                clientContext.Load(regSet);

                // Execute the query to the server
                clientContext.ExecuteQuery();

                // Display the updated calendar type
                Console.WriteLine("Calendar Type: " + regSet.CalendarType + "; Alernate Calendar Type: " + regSet.AlternateCalendarType);
                Console.ReadLine();
            }
        }

        private static SecureString GetPassword()
        {
            ConsoleKeyInfo info;

            //Get the user's password as a SecureString
            SecureString securePassword = new SecureString();
            do
            {
                info = Console.ReadKey(true);
                if (info.Key != ConsoleKey.Enter)
                {
                    securePassword.AppendChar(info.KeyChar);
                }
            }
            while (info.Key != ConsoleKey.Enter);
            return securePassword;
        }
    }
}

Result