It's common to use the same time zone abbreviation throughout the year. E.g. in Europe you'd be on CET or CEST depending on time of year, but it's common enough

It's common to use the same time zone abbreviation throughout the year. E.g. in Europe you'd be on CET or CEST depending on time of year, but it's common enough to use "CET" for both that it's a de facto standard. Not a hill to die on at this point. CET in this informal way means "CET OR CEST depending on which of them is current at the location at the given time". This can give rise to ambiguity in places, but it's pretty rare that it does.