Is there any difference between saying "PDT all year round" and "MST"? Though I do agree that the graphic could be better, as the important information is real

Is there any difference between saying "PDT all year round" and "MST"? Though I do agree that the graphic could be better, as the important information is really just: will the winter time move/not move 1 hour, and will the state observe/not observe daylight savings time. They need to add crosshatching or similar to indicate the latter info.