What does 日数 mean?
日数 is a Japanese noun meaning “number of days” in English. It is written as 日数 in kanji, にっすう in hiragana, and nissuu in romaji. This word is part of JLPT N1 vocabulary.
Example sentence
長い日数ではなかったが、そこに滞在された。
There they stayed for a few days.