You’d think that this would be obvious in the year 2010, but it’s ridiculous the number of companies that advertise on-line events, for which they are obviously seeking a global audience, and don’t include the time zone. Not only does most of the world NOT run on your timezone, but most of them don’t have a clue what time zone you’re in. And don’t give me that B.S. that “your customers know where we are”, because, if you have multiple offices, I guarantee that at least some don’t. And if you are doing it at a partner or customer office that is not in your head-office time zone, how are they supposed to even have a clue?
And learn what daylight standard time means. It’s amazing how many events I see for 11:00 EDT in December (not possible!) or EST in July in New York (again, not possible!). And don’t take the timezone shortcut and just use ET, CT, or PT. Remember, not all provinces and states (like Saskatchewan and Arizona) use daylight savings time, and the usual assumption is that if an abbreviation is used, you mean xDT in summer and xST in winter.
And if there is any possibility of confusion (and with timezones there usually is), spell the timezone out. BST can mean British Summer Time, Burma Standard Time, or Bangladesh Standard Time.
Don’t be a Dummy! Use the fully qualified timezone.