Linking to iCal/Outlook event issue

I’m trying to get a .ics file set up to create a calendar event. Eventually I will be linking to this .ics file from an HTML document, but for now I just need to get a working .ics file set up. I created the following in a text editor:

BEGIN:VCALENDAR
VERSION:2.0
CALSCALE:GREGORIAN
METHOD:PUBLISH
BEGIN:VEVENT
DTSTART:20100624T120000Z
DTEND:20100624T130000Z
SUMMARY:Company Relaunch
DESCRIPTION:Company Relaunch
END:VEVENT
END:VCALENDAR

But when I try to open this in Outlook or iCal I get errors saying that it is unreadable. What am I doing wrong here?