Why a seven-day cruise might be viewed as either six seven or eight days long?

A seven-day cruise can be perceived as six, seven, or eight days long depending on how one counts the duration. Some may consider it six days if they view the departure and return days as partial days rather than full days spent on the cruise. Others may count it as eight days if they include both the embarkation and disembarkation days. Ultimately, the perception varies based on individual interpretations of the itinerary and the timing of activities on those days.