Any business day can be a settlement day, but there can only be one DATE OF RECORD per dividend declared. To receive the dividend you must have owned the stock on the DATE OF RECORD.
I bought FTR on March 1st. My SETTLEMENT date was March 4th (T+3, or Trade Date plus 3 business days after the transaction occurred). I am the owner of record of the shares starting on March 4th. I will be the owner of record until 3 business days AFTER I sell the shares. If I were to sell today(March 7, the ex-div. date)I will be the shareholder of record March 8th. and 9th., but not the 10th (sell settlement day). I would get the div because I was the shareholder of record on the RECORD DATE, March 9th.