Do the numbers of days you have been playing for change anything?

Whenever I sleep or work through the night, the game tells me what day I am on. While I am around Day 20, I have not noticed anything change significantly about the number of enemies or difficulty in my world. Is the number of days my character has been playing for affect anything like the types of enemies attacking my base or the items that I’ll find? Is there a limit to the number of days my character can be alive, like a time limit on my campaign?