I just created an "add to calendar" file for one of my webinars. It's set up for 12 CT. When I add it to my calendar, it is on the right time, but the description says 5-6 UTC time zone.
I am also experiencing this frustration with inaccurate timezone abbreviations for AEST. EST is actually an American timezone, but Marketo uses this as the AEST timezone abbreviation which is causing us much confusion when it come scheduling things internationally. Really looking forward to having an 'A' added to the EST some time soon!