Check out the
standard at
faqs.org.
A partial implementation that allows you to synch your ACES 3.5 calendar with Outlook and probably your palm, KMail and Evolution is in the tree maintained by Malte.
I only tested it with Outlook when I finished it. Recurring events ("replace ass gasket every Monday") require timezone information in the standard, and ACES doesn't carry that, so I kludged it to the point where Outlook liked it since that's what the client (Sloan/MIT) wanted. Other calendar software may not fall for the kludge.
But non-recurring (single) events are kosher by the standard AFAIK.
And OpenACS 4 has timezone information, and though acs-events doesn't use it yet there's a hook for it. So eventually we'll be able to put out kosher iCalendar format files for recurring events, too.
BTW the format was developed by MS and Lotus and is as bad as you'd expect from hearing that.
