Air NZ AKL has a 6days on, 3days off shift. You rotate round start times of 0600, 1100, 0630, 1400, 0700, 1500 then back to 0600 starts. Biggest problem was not being able to find your car in the carpark at the end of each shift.
After 7 years of lobbying management now have allowed a tempory trial shift of something like 2on,3off, 3on, 2off.
I'm still looking for my ideal shift of 1on, 6off.