I have not used the calendar feature but I did see where there is an "appointment" object which is a subtype of "message".

There is a Novel Developer kit that covers the GroupWise object API -and this is in chapter 3 in the version I have. You can get the document off the Novell site if you don't have it or you might have it on your own machine. Our GW install left a pdf called gwobjenu.pdf on the local drive under novell\ndk\doc\gwobjapi.

Hope this helps a little.

Dan Gallagher