It's been almost 15 years and I still miss it -- it was great! We had 9 hour days Mon-Thu, either 0 or 8 hours on Friday.
The company originally instituted it in California to meet a mandate to reduce pollution by 20%. They shut down 1 day out of 10 + took credit for 10% reduction in employee commuting.
It was popular enough that they spread it to other sites.
One side effect was that the week started/stopped at noon Friday. Part of the plant was unionized and union rules said anything over 40 hours in a week was paid at overtime rates, and if the company scheduled you for less than 40 hours work in the week you still got paid for 40 hours. Nothing in the contract specified when the week started. So it was timecards at noon Friday.