public static class Calendars
{
    // Retrieve all calendars for device
    public static Task<IEnumerable<Calendar>> GetCalendarsAsync();

    // Retrieve the calendar for a specific ID
    public static Task<Calendar> GetCalendarAsync(string calendarId);

    // Retrieve all events for a specified range/calendar
    // Null values for parameters will result in default values being used: 
    //     calendarId will return events from all calendars
    //     startDate will default to the Now
    //     endDate will default to startDate+14 days
    public static Task<IEnumerable<CalendarEvent>> GetEventsAsync(string calendarId = null, DateTimeOffset? startDate = null, DateTimeOffset? endDate = null);

    // Gets more detailed information about a specific event by the event ID
    public static Task<CalendarEvent> GetEventAsync(string eventId);
}

public class Calendar
{
    public Calendar();
    public Calendar(string id, string name);

    public string Id { get; set; }
    public string Name { get; set; }
}

public class CalendarEvent
{
    public CalendarEvent();
    public CalendarEvent(string id, string calendarId, string title);

    public string Id { get; set; }
    public string CalendarId { get; set; }
    public string Title { get; set; }
    public string Description { get; set; }
    public string Location { get; set; }
    public bool AllDay { get; set; }
    public DateTimeOffset StartDate { get; set; }
    public DateTimeOffset EndDate { get; set; }
    public TimeSpan Duration { get; } // if this is AllDay, then the Duration will be 1 day
    public IEnumerable<CalendarEventAttendee> Attendees { get; set; }
}

public class CalendarEventAttendee
{
    public CalendarEventAttendee();
    public CalendarEventAttendee(string name, string email);

    public string Name { get; set; }
    public string Email { get; set; }
}