How do I produce ics file from asp.net mvc for consumption in eg google calendar?

Question

I'm writing a little proof-of-concept for a website where calendars/schedules should be exposed for users' inclusion in phone/web calendar applications.

First I'm trying with google calendar. My code aim to create a calendar with a singe event -- at any time it's "tomorrow at ten a.m.". I'm using dday.ical to produce ics.

I've written code below and published to http://mdftaxi.azurewebsites.net/

Ics can be downloaded from http://mdftaxi.azurewebsites.net/api/Calendar/1

Google appear to accept the calendar when I add with url above.

However -- nothing is shown in google calendar?! What am I doing wrong?!

Thanks for any help,

Anders, Denmark

    public class CalendarController : ApiController
{
    public HttpResponseMessage Get(int id)
    {
        var iCal = new iCalendar
        {
            Method = "PUBLISH",
            Version = "2.0",
            Name = "Taxi" + id
        };

        var evt = iCal.Create<Event>();
        evt.Summary = "Test";
        var dt = DateTime.Today.AddDays(1).AddHours(10);
        evt.Start = new iCalDateTime(dt);
        evt.Duration = TimeSpan.FromHours(1);
        evt.Description = "This is body";
        evt.Location = "location";
        evt.IsAllDay = false;
        evt.UID = Guid.NewGuid().ToString();
        evt.Organizer = new Organizer("andersjuulsfirma@gmail.com");

        var res = new DDay.iCal.Serialization.iCalendar.iCalendarSerializer().SerializeToString(iCal);

        using (var file = new System.IO.StreamWriter(Path.GetTempPath() + "out.ics"))
        {
            file.WriteLine(res);
        }

        var result = new HttpResponseMessage(HttpStatusCode.OK)
        {
            Content = new StringContent(res)
        };
        result.Content.Headers.ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("attachment")
        {
            FileName = "calendar.ics"
        };
        result.Content.Headers.ContentType = new MediaTypeHeaderValue("text/calendar");
        return result;
    }
}

Edit: Found solution. At least it appears to solve the problem if I strip it down somewhat:

        var iCal = new iCalendar
        {
            Version = "2.0"
        };

        for (var i = 0; i < 3; i++)
        {
            var evt = iCal.Create<Event>();
            evt.Summary = "Test";
            evt.Start = new iCalDateTime(DateTime.Today.AddDays(i).AddHours(20));
            evt.Duration = TimeSpan.FromHours(1);
            evt.Description = "This is body";
            evt.IsAllDay = false;
            evt.UID = Guid.NewGuid().ToString();
            evt.Organizer = new Organizer("CN=John Doe:MAILTO:john.doe@example.com");
        }

        var res = new iCalendarSerializer().SerializeToString(iCal);
        using (var file = new System.IO.StreamWriter(Path.GetTempPath() + "out.ics"))
        {
            file.Write(res);
        }

        return res;