also: ひかず
number of days
Refers to a count of days, such as the length of a period or the total days needed.
完成までに必要な日数を見積もってください。
Please estimate the number of days needed to complete it.
The number of days for the trip is one week.
This procedure takes a number of days to complete.
I'm counting the number of days until departure.
There aren't enough days left to prepare.
I calculated the number of days spent in the hospital.
total days; aggregate number of days