Why it seems to be a common idea that ATCOs do not need to be that smart? (Or that's what I understand from #2657.) Certainly they should be smart enough to be able to answer a simple DST question without "an explanation in simple terms". Kids aged 12 do such calculations at school so how about starting using your brain?
Also, avoiding typing multiple question mark/exclamation marks/smilies in a row may help the impression.