Another idea, if you need to use a remote hosted calendar, would be to check out SuperCalendar...it is geared towards groups and non-profits - and free!
I used it for a photographic organization site as I could not incorporate scripts and it proved to be reliable, very interactive between members and I could custom to my site. It would automatically update events and was easy to use.
Another plus is great webmaster who continually added new features and actually answered my emails!
Dlynn ~SitePoint Moderator~
PawPrint Designs by WebKat "Let's keep Ethics on the Web"