Well I heard it on the documentary on BBC Alba with the two girls cycling in the Western Isles. (Kerry 's Kirsty: Rothan gu Robhanais). The commentator said "a' mhadainn eile" and the subtitles said "The next morning". I also heard "an Latha eile" on another programme but I can't remember. There are some good progammes on BBC Alba. Maybe he meant another day and it was translated loosely.