Daylight saving time is a controversial practice. Whether it's a valued way to extend the hours of sunlight, or an archaic, agrarian artifact, it's here to stay. But there should be one aspect of DST that we can agree upon: its grammar.
Two common mistakes occur around DST, with the first not being unique to it. An extra 's' likes to appear at the end of certain words: going forwards, leaping backwards, moving towards. In all these instances, the last letter is extraneous and can be dropped without sacrificing meaning. The same goes for Daylight Savings Time. In this context, "saving" is an adjective describing "time", not a noun unto itself.
The second error is far more egregious as, unlike a superfluous 's', it can actually obfuscate meaning. When specifying an hour, standard time is sometimes used where daylight saving time would be correct. Since 2007 in the United States, daylight saving time starts on the second Sunday in March and ends on the first Sunday in November. DST is therefore in effect the majority of the year. During these months, the correct way to indicate 6:00 PM on the East Coast, for example, is 6:00 PM EDT, or Eastern Daylight Time — not EST. 6:00 PM EST is in fact 7:00 PM EDT, and your audience may do this mental gymnastic only to find themselves an hour late for a presentation.
An academic difference? Hardly. In May 2000, Sega invited me to a teleconference that they said would be held at 1:00 PM EST, even though at that point in the year, daylight saving time was clearly in effect. I assumed their acronym to be in error and so dialed into the conference at 1:00 PM EDT. Sure enough, their public relations reps were on the line and ready to break their news.
I got off the phone a half-hour later and called a fellow journalist to share what I'd learned. He was baffled: "What teleconference? The call isn't until 2:00 PM. Maybe you're just confused and are mistaking some rumors you read online for the conference?" He and several others had taken the EST timestamp to heart, and the Sega reps had to play a recording of their conference an hour after it was held for all the latecomers.
Rarely are my efforts to point out this error understood. When a director told me that his movie would be on television at 6:00 PM EST, I asked him, "EST or EDT?" He failed to clarify the matter when he wrote back, "Eastern." Others, not understanding what EDT means, stubbornly insist EST.
If you can't be correct, then be vague. Can't remember what the acronyms mean, or which one goes with what time of year? Use neither. Just say "Eastern", and your readers will understand you to mean whatever the hour currently is in that time zone.
We know how to prevent the heartache of DST; follow these simple tips to avoid the headache as well.