If you’ve been writing your time zones with an “S” in the middle since March, you’ve been doing it wrong. That’s right: For most of the year, it’s actually “EDT,” “PDT,” etc., as in, “The game starts at 7:30 p.m. EDT.”
The “D” stands for “daylight,” as in “daylight saving time,” which ends this weekend when the clocks “fall back” early Sunday morning. And in case you’re curious, the “S” stands for “standard,” and it will be the correct middle letter in time zone abbreviations come Sunday.
So, if you haven’t already been doing so, put the “S” back in your time zone abbreviations, but don’t put it at the end of “saving”: It’s daylight saving time, not “daylight savings.”