I used to work for a company that did them. Your usual deliverables would be paused, including meetings.

It wasn’t “more”. They were great. Most of our internal tooling was prototyped that way, and that tooling was super awesome… because it directly solved the real issues we had in our processes.

My current company is “you can during the designated hackathon events, but you still have to do everything you usually would”. Which is absurd because it means that we don’t always have the option to work late for free.