At the suggestion of @magistrazee, I went ahead and activated the Group Event Calendar feature for the groups on Amicitia.
I thought that this was not a useful feature at first when I was trying to implement it, but now I think this can be a useful too. @magistrazee had asked if we had one in order to coordinate events with the members of various groups – and now we do! So, give it a shot and if you have any suggestions, let me know!