Do you mean ET? Most areas but not all within ET do follow daylight savings. How do you accommodate for the areas within ET(ETZ) zone that do switch between UTC -4 and -5 or EST and EDT) and those that don't?
As a sibling comment mentioned, when available or used(big ifs) calendar software often takes care of this.
As a sibling comment mentioned, when available or used(big ifs) calendar software often takes care of this.