my work uses two different 4 day setups. we run 24/7/365 coverage. one shift is either 10 hour/day Sun-Weds or Weds-Sat, the other setup is a rolling 10 hour/day 4 days on, 4 days off. One gets you a consistent schedule, but you're regularly working a weekend day. The other is less consistent (work days cycle back around every few weeks) but you're for sure to get full weekends now and then.
that website smells like dr bronner's soap