I hope this helps.
CET is always Central European Time
CDT is always Central Daylight Time (US)
CST is usually Central Standard Time (US), but after the time change daylight savings becomes the standard for the entire US and usually Europe too, so many posters will just assume you already know it's really daylight savings time.
As you can see, CET is never used except for Euro centric events or events expected to attract European players such as scenarios. Times for Special Events are given in Eastern (US) time, exactly to prevent confusion with CET, CST and CDT.
For event times given only in EST (which means daylight savings time in both US and Europe atm
), you can use this table.
Helsinki +7
Europe +6
UK +5
Eastern 0
Central -1
Mountain -2
Pacific -3
Anchorage -4
Hawaii -6
Melbourne/Sydney -10 (I haven't checked these in awhile)