It's neither. It's like "th" in "this" and "that" (Arabic letter ذ). I usually represent this letter as "zh" because "th" represents the sound in "think" (Arabic letter ث). I also use "dh" for the backward d, which sounds a bit like in "dub", which represents the Arabic letter ض which you find in Ramadhaan.
Asalaamu Alaikum,
Most miracles have some explanation for it... Is this legit?
I thought it was "Adhan", with no z in the spelling. Is this like "Ramazan"?