Five things you need to know today, and a three-day weekend

Good morning, Boston — and Happy Rosh Hashanah. Here is an abbreviated version of the five things you need to know to start your busy business day. ACK or bust An ad campaign from the Nantucket agency SAND played up the insider jokes and points of pride that Nantucket residents know all too well — and washashores may not understand. The campaign helped sell more than 4,800 specialty license plates, Grant Welker reports. A 20-story tower pitched in Quincy Center An affiliate of Quincy-based…