Unfortunately, the calendar stuff's been in transition. Shannon's more on top of what events are, but she doesn't have the ability to edit the contents of that sidebar due to... um, oogy technical issues.
Currently under consideration is replacing that sidebar with a simple link to a bulletin board on these forums, which Shannon could just post things to. It'd have the disadvantage that the threads wouldn't be sorted by the date of the event, but I think the convenience factor may overcome that.