I\'m trying to parse a file that has the following format:
BEGIN:VEVENT CREATED:20120504T163940Z DTEND;TZID=America/Chicago:20120504T130000 DTSTAMP:20120504T1640
Spiting into lines and use IndexOf(":") may be enough for simple ICAL files instead of RegEx.
Check out if there is already existing ICAL parser and related questions ical+C#.