That sounds good, and it is true as well. The elimination of all Fridays and legal holidays brings more relaxation - less work and burden per week - nevertheless it increases the annual working hours and the number of free days. For the usual 35-hour-week with 4 days at 7.5 working hours and a Friday at 5 working hours, see the following example for 252 days:
36 weeks at 35 hours in a 7-day-week: 1260 hours (72 free days)
42 weeks at 30 hours in a 6-day-week: 1260 hours (84 free days)
Every 6-day-week contains fewer working hours, and 12 additional free days are turning up. (Similar calculation for 40-hour-weeks. I suggest 4 days at 8-8.5 hours.)
A 6-day-week would give us more annual working hours because of the elimination of the legal holidays - nevertheless we would have more free days.
This paradoxon has to be explained. On average we work 5 hours a day, in both weeks. Imagine the 7-day-week emerging from a 6-day-week thru inserting a 5-hour day before the weekend. You can also take 2 Fridays before the weekend to create an 8-day-week. The crucial weekend, which is so necessary for the recuperation, is postponed, and that is dangerous. The Friday is doubly hard because of the exhaustion by the preceding 4 working days. - Furthermore, we gather incomplete days to create full days and free days.
It is obvious that we have to get rid of the Friday. The slight aberration of the optimal working rhythm from the Gregorian calendar week can be corrected thru the elimination of one day.
We must move with the times. Nowadays the working hours per week are so minimized that we can spread them over four days. But 3 free days per week would reduce the annual working hours, and superimposing a 6-day-rhythm over a 7-day-week would be nonsense.
We lived in the illusion that a decrease of weekly working hours would diminish the annual working hours. Wrong. So no one has ever found the time and disillusion to think over the kangaroo calendar.
Concerning the health we must appreciate to work one day less according to the law: aggregation brings aggravation brings aggression brings ailment.
The date lines would not be changed because the months are the same.
What are we waiting for? Thru this once-in-a-millennium change we could work more without feeling it. That would give us ca. 5% of the total economic volume - billions!
In addition we would get some percent more health.
We need it.