iCalendar files provide a standard, structured format for calendar information and can contain multiple events per file with lots of different attributes (see the RFC). Here's an example with one event. Multiple calendar events, each bracketed by BEGIN:VEVENT / END:VEVENT, can be included in one calendar file which begins with BEGIN:VCALENDAR and ends with END:VCALENDAR. Read the RFC for details (and notice that the X- components are "experimental" and vendor-specific, not necessarily needed in any SAS support.
iCalendar support would allow one to create events in SAS and have the program create the format correctly, providing some things automatically (for example PRODID: would be SAS-specific but static for each version). One of the best use cases for this: if you create these files on a web server, most calendar programs (like Outlook, iCal, and Phone calendars) can "subscribe" to them so that as they are updated the updates get reflected in those calendar visualization tools. This can be a good way to "visualize" event-based data. If you do something Outlook-compatible (or if the standard supports it), you can use HTML in the X-ALT-DESC. I wrote a SAS program that creates these files via PUT, that includes links to performance data charts. One calendar entry for each day links to multiple charts for that day.
If would be good if PROC CALENDAR could output this file type.
Optional, possible, extensions/ideas:
DATA step able to read a file of this type and create a SAS dataset with one observation per VEVENT
The ability to have an ODS 'timeline' chart type to graph a timeline given a SAS dataset containing this info
support for xCal, the XML format of iCalendar
Reading .ics files via URL (similar to how Outlook/iCal "subscribe" to a calendar.
SAS Institute to join Calconnect.org if you haven't already
The main trick to handling this file type is appending new events - you have to write everything but the END:VCALENDAR, then write the new VEVENT info, then add the END:VCALENDAR.
There are a few sites and mailing lists related to iCalendar, but I would start with Calconnect.org, an organization intent on standardizing calendar info and exchange until it "just works" like e-mail .