Can the word days be possessive?

Answer 1

Yes, the word day (singular) or days (plural) can be possessive. Examples:

The day's activities were exhausting. (the activities of the day)

The days' length are getting shorter. (the length of the days)

Answer 2

Yes, the word "days" can be made possessive by adding an apostrophe and an "s" at the end, like this: "days'". This indicates that something belongs to or is associated with the days.