I'm fairly sure it means that you work 80 hours over 9 days (instead of 10), which can actually be pretty nice, because its fairly rare for professionals to actually work 9-5. To me it seems to codify an existing trend, and provide a benefit that acknowledges the reality of work. personally I don't think this represents a lack of workers rights, but an improvement by offering a more flexible schedule.

“The 9/80 work week… occurs over a 2-week period as follows: employees work seven 9-hour days in a 2-week period, one 8-hour day and then receive one “free” day off every other week.”

https://workfamily.sas.upenn.edu/glossary/n/nineeighty-work-...

Google is your friend.

Working 80 hour days, 9 days a week. Gotta make all of our goals in crunch.

9/80 means you work 9 days over a two week period, 9 hours per day, with 8 hours 1 day.

>What the US desperately lacks is a federal workers' protection laws.

Please take the time to look up what 9/80 means before dropping a bunch of political conjecture.