The 5 month time skip happened in chapter 190

Five months pass after the aging devil arc

It’s why it’s kinda weird how they go from fighting a primal to brunching it up together

My reason for this is how the world has become complacent in the chainsaw devil outbreak. Killing them has become part of the day to day. And that guy who was trapped in the aging realm even has a job now. They even mentioned “it’s good we got to return to our normal lives”

No way all of this happened just a couple days after the aging devil arc. If we assume there hasn’t been a 5 month then it’d only been a couple weeks at most since the chainsaw outbreak. It would be a little weird how quickly society adjusted to the chainsaw monsters.