How to: Programmatically create a custom calendar
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
This example creates a new Calendar folder named PersonalCalendar, and then creates a new Appointment item and adds it to the Calendar folder. The code then displays the Calendar folder.
Applies to: The information in this topic applies to VSTO Add-in projects for Outlook. For more information, see Features available by Office application and project type.
Example
private void CreateCustomCalendar()
{
const string newCalendarName = "PersonalCalendar";
Outlook.MAPIFolder primaryCalendar = (Outlook.MAPIFolder)
this.Application.ActiveExplorer().Session.GetDefaultFolder
(Outlook.OlDefaultFolders.olFolderCalendar);
bool needFolder = true;
foreach (Outlook.MAPIFolder personalCalendar
in primaryCalendar.Folders)
{
if (personalCalendar.Name == newCalendarName)
{
needFolder = false;
break;
}
}
if (needFolder)
{
Outlook.MAPIFolder personalCalendar = primaryCalendar
.Folders.Add(newCalendarName,
Outlook.OlDefaultFolders.olFolderCalendar);
Outlook.AppointmentItem newEvent =
personalCalendar.Items.Add
(Outlook.OlItemType.olAppointmentItem)
as Outlook.AppointmentItem;
newEvent.Start = DateTime.Now.AddHours(1);
newEvent.End = DateTime.Now.AddHours(1.25);
newEvent.Subject = "New plan";
newEvent.Body = " Meet to discuss new plan.";
newEvent.Save();
}
Application.ActiveExplorer().SelectFolder(primaryCalendar
.Folders[newCalendarName]);
Application.ActiveExplorer().CurrentFolder.Display();
}