When I worked for Northrop, they offered a "9/80” schedule. Every pay period, you would work 80 hours in 9 days. Monday thru Thursday, you would work an additional hour (so 9 total), then have every other Friday off.
I never did this personally, but I worked with civilians that did 9 80s. If management isn't willing to consider "exotic" schedules, 9 80s seem like a really good starting point and a pretty sweet deal