There is always a first, he he.http://qz.com/142199/the-us-needs-to-re ... our-apart/The east coast would be seven hours behind continental Europe, but one hour closer to time zones in Asia.
I preffer to think of "menos sete horas" since it´s a definitive thing there, so no "atrasado sete horas", it could be exchangeable in some contexts, but could give the impression that at the DST time (horário de verão) one would set the clock seven hours back.
Of course, not everyone (let´s not generalize, but just in case...)
Indeed at the STD generally clocks are set one hour ahead (atrasa uma hora) at the beggining of it, and then set one hour back (adianta uma hora) at the end.
There is, you (and everyone sets as well) set the clock one hour ahead and then an hour back.
While on the subject, to say that you got to a place "uma hora adiantado" you would say that you got there one hour (or more hours) earlier. Or, if otherwise (atrasado) you got there one hour (or more) late.
Ah, and chances are that your clock is one hour slow/behind (an example: the clock of your computer), so it´s not a matter of setting. It just decided to slow on its own.