EST is shorter than Eastern and more easily recognizable than ET, which is a more heavily overloaded acronym. I'm sure it's used by people who are aware of the

EST is shorter than Eastern and more easily recognizable than ET, which is a more heavily overloaded acronym. I'm sure it's used by people who are aware of the technical meaning and not forgetting. There's no quick and reliable way to refer to non-EDT EST during the non-daylight months without mentioning the absence of daylight savings time or specifying the UTC offset.