Pixel42
Schrödinger's cat
Many people can't work 6 days a week, even for just half the year, because they have other responsibilities (eg children or elderly relatives to care for) that simply can't be accommodated in such a regime.
Many others would simply prefer to spread their working hours over the whole year, as now, than to work so intensively for half of it and then twiddle their thumbs for the other half.
How would you decide who gets to work in the winter months and get the summer off, and vice versa? Most people will prefer to have the summer months off, so if you let them choose vital services will be severely undermanned in the summer.
Many others would simply prefer to spread their working hours over the whole year, as now, than to work so intensively for half of it and then twiddle their thumbs for the other half.
How would you decide who gets to work in the winter months and get the summer off, and vice versa? Most people will prefer to have the summer months off, so if you let them choose vital services will be severely undermanned in the summer.