It just takes ONE NIGHT for everyone to feel the difference.
...and yet people are not involved in the process.
[p/s: イア～... I was rewatching Clannad After Story when I reached episode 22 where a song that mentions about season change is played in the background; Chiisana Te no Hira. So, I thought myself that somehow what Nagisa-chan was talking also applies to the city I currently live in, hence my post. XD
Here is the link to that scene]