Why would you ever need full week coverage? Just tell hires that Monday Tuesday is the schedule. It's not like factory work where the machines need to run constantly.
"Why would you ever need full week coverage?"
Because critical issues happen and typically businesses want them solved ASAP rather than waiting a week til people come in again.
This is development we're talking about, not ops. Make sure your deployment plan includes rollback capability, then let ops do what ops does. Almost never should you encounter a dev issue that needs emergency code pushed in less time than it takes to make a phone call and get someone to remote in.