noun
number of nights stayed
Used in contexts such as hotel bookings, travel itineraries, or accommodation statistics.
今回の旅行の宿泊数は三泊です。
The number of nights for this trip is three.
宿泊数に応じて料金が変わります。
The price changes depending on the number of nights stayed.
泊数 is a more casual or abbreviated way to say 'number of nights', often used in travel contexts.
Compound of 宿泊 (lodging, overnight stay) and 数 (number).