EST or EDT? Get your time zones right in your marketing communications

This is one of my pet peeves, but it's also something that should be important to marketers of all types. I can't even tell you how many marketing communications I've seen (webcast announcements, event emails, direct mail pieces, etc.) where companies get this wrong. And it should be pretty simple.

Whenever you're writing a time on a communication that's going to anyone outside your immediate geographic area, you should specify a time zone. That's obvious. But getting it right is a challenge for many marketers.

It's the second week of April. Let's say you're in New York right now. You're on Eastern Standard Time, right? Wrong. You're really on Eastern Daylight Time.

Back to Time Zone 101 class: The second word in the the time zone phrase is meant to express whether or not you're on Daylight Saving Time. So in the U.S., from roughly November through March (the dates vary each year), you'd say "Eastern Standard Time." But during the summer months you'd say "Eastern Daylight Time."

So many businesses get it wrong on their voicemail greetings, on the hours posted on their website, and many other places. They'll just say "We're open 9am-5pm Eastern Standard Time" and they leave that message active all year round. So what are you saying, your company doesn't observe Daylight Saving Time? Their message is wrong more than half the year.

Don't want to think about it? Here's the amazingly simple workaround. If you're only communicating with a U.S. audience, just say "Eastern Time." If you don't use that middle word, you'll be less precise but you'll always be correct. People should always know what you mean. (The only place that might backfire is in a couple exceptions like Arizona and Hawaii, the only two states where Daylight Saving Time isn't observed. A few U.S. territories also don't observe DST. But unless you're communicating specifically with one of those groups, the general rule applies.)

Now if you're communicating with a potentially global audience -- let's say a webcast -- you should make sure you're specifying Standard or Daylight. Alongside that, you should also list your offset from Greenwich Mean Time (GMT), the standard upon which all time zones are based and most people outside the U.S. should be able to calculate from.

So if I'm holding a webcast today (in April) in New York at 2pm Eastern Daylight Time, here's how I'd write the time:

2:00 p.m. Eastern Daylight Time (GMT -4, New York); or
2:00 p.m. EDT (GMT -4, New York)

Note what I've done here. I've told them the time zone (Eastern Daylight Time or EDT), I've also given them an offset from GMT (4 hours behind GMT), and I've told them the major city of the time zone (New York). With this info, just about everyone should be able to figure out when the webcast starts.

Of course be careful when you're doing this, because the offset changes from Standard to Daylight time. If it was December and Daylight Saving Time wasn't in effect, the offset changes to (GMT -5, New York). Remember, GMT never changes.

Once you get the hang of it, it's pretty simple. And I'm amazed schools don't teach this stuff -- or at least many people didn't learn it. You might look at all this and say, "But Michael, is anyone really going to get confused if I get EST and EDT mixed up? Won't they know what I mean?" If you're dealing with a U.S. audience, they'll probably figure it out and you won't have much confusion. But some people will notice your error. Why make a simple mistake like this when it's easily avoidable? You don't want to seem dumb in your marketing communications, do you?