The problem is not that they had to work on those days.
The problem is that they had two consecutive shifts.
The alternative is that the hospital hires enough people so they can schedule them such that everybody has time to go home relax and sleep after they are done with a shift.
The problem is that they had two consecutive shifts.
The alternative is that the hospital hires enough people so they can schedule them such that everybody has time to go home relax and sleep after they are done with a shift.