public class User : IdentityUser
{
    public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<User> manager)
    {
        // Note the authenticationType must match the one defined in CookieAuthenticationOptions.AuthenticationType
        var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
        // Add custom user claims here
        return userIdentity;
    }

    public User()
    {
        Calendar = new Calendar();
    }

    public Calendar Calendar { get; private set; }
}

public class Calendar
{
    public int Id { get; set; }

    public Calendar()
    {
        CalendarEvents = new List<CalendarEvent>();
    }

    public virtual List<CalendarEvent> CalendarEvents { get; private set; }
}

public class CalendarEvent
{
    public int Id { get; set; }
    public string title { get; set; }
    public string date { get; set; }
    public string start { get; set; }
    public string end { get; set; }
    public string url { get; set; }
    public bool allDay { get; set; }

}