When getting a travel insurance quote, make sure to enter the correct return date.
The return date is the date that the traveling party is scheduled to arrive back at their home after the trip. Travel insurance will cover the traveler from their home, through the trip and back to their home. So the return date is not necessarily the date that a return flight is scheduled, or when a cruise ship returns to the home country, but when the traveler arrives back at their house once the trip is completed.
Always refer to the certificate of insurance for details.