The extra-calendar days are all holidays and follow weekends, at the end of a month. The extra-calendar days are not days of the week (i.e. not Monday, Tuesday,...). Every month is the same.
This was proposed by a American engineer, Warren Barlow in Washington DC. I think I saw it in People's Almanac in the 1970's. (Reference needed!) Each month starts on a Monday and ends with the 28th on a Sunday. (Also, the 28th of April is always Easter Sunday.)
Every month has 28 days plus a variable number of extra calendar Nodays
.
The extra calendar days are not days of the week, they are just
numbers, or ordinally the 3rd day of Summer Festival
.
(Seems like they should also be referred to as the 29th, etc, for business purposes.)
The Summer festival would have an extra day added to it in leap years.
There would be no irregularities in the first through last working days of the month.
However, the Nodays would still be business days that companies would have to account for.
Perhaps business would be suspended as much as possible during those days?
Reportedly, Barlow
calculated immense savings by doing this calendar reform.
Note emphasis on Christian Holidays. Also, the Northern Hemishere is favored — extra days are added in the Northern summer.