Pssst - it was a joke.
That happens to be the French revolutionary calendar.
Those darn French revolutionaries are always trying to steal good ideas from Dopers!
The jjimm, AKA French Revolutionary calendar has an advantage he didn’t even mention - it is a “perennial” calendar - that is the same calendar works every year with a given date always falling on the same weekday.
(One important difference in execution between him and the French Revolutionaries - the peasants complained about the new calendar because it only gave them one day off in ten, to attend a “temple of reason” instead of one day off in seven, to attend church. They lengthened the week, but not the weekend.)
There have been several proposed calendar reforms producing a perennial calendar, usually observing that while 365 has awkward factorability (5 * 73), 360 has tons of factors and 364 is pretty good (in particular, it divides by 7, our current week length). Removing 1 or 5 days and making them non-weekdays (2 or 6 on leap years) allows you to divide the rest into equal sized groups.
None of which will ever happen, of course.
Personally, I prefer the so-called “World Calendar” proposal, which takes one day out, leaves all the month and day names in place, and leaves us with four identical three month periods:
http://personal.ecu.edu/mccartyr/world-calendar.html
Of course, this calendar assures 4 Friday the 13th’s every year …
Only difference is the French tried to keep to the two-day weekend, which meant there was an eight-day work week. Non, merci!!
Or nine. yabob is correct.
And when I told the people in the hospital I was Robespierre, they gave me a jacket with no sleeves!