Are you looking for 30 day cruises that leave from New York, NY? As of today - April 2, 2025 - there are just 3 such cruise options. These cruise options are offered by two cruise lines - Holland America (just 2 sailings, both of them on Volendam) and Cunard (just 1 sailing on Queen Mary 2).
In the following table you can see all 30 day cruises that depart from New York sorted by departure date.