I’ve decided and my work colleagues were agreeing that it’s a good idea
Currently in a 7 day week there are:

5 week days
2 weekend days

The problem with this is that the weekend isnt long enough to recover for the next week, but the week also isnt long enough to get everything done.

So, my proposal is the 9 day week:

6 week days
3 weekend days

That way you increase the amount of rest days and the length of the working week. It does mean that the percentage of working days in the year would go down from 71% to 67%, but i think it would work better as the week is longer and recovery time is more beneficial.

The origins of this thinking came from UK bank holiday weekends which are public holidays usually falling on a Monday Tuesday or Friday which total approximately 8 in the UK. And everyone seems so much better after a break like that. So we should have that length all the time -right? And i always think that the week is never quite long enough to get everything done, so it should be extended by a day hence my new version of the week