I know people who have to work 3 days in the morning, 1 day rest, 3 days in the afternoon, 1 day rest, and 3 days at night. I understand that there are places w

I know people who have to work 3 days in the morning, 1 day rest, 3 days in the afternoon, 1 day rest, and 3 days at night. I understand that there are places where they have to keep the workers in rotation, but why don't they change this monthly, for example? I don't think that in 3 days your internal clock can adjust.