Don't try to add your post into the GRAPHIC calendar.
At the top of the "Forums" page look for "Rally Callendar" near the middle top and click on it.
In the upper Right Corner look for "Add New Event" next to "Monthly View" and "Show Today", click on "Add New Event"
In the drop down menu choose which type of time frame you want and click on it.
This should open a new window showing the form to fill out all in text with appropriate choices for the month, day, year you want your event to happen
Enter all the data and click on "save" at the bottom.
Frederick - The Scaleman