If I ruled the world - Part I

So me decided to go on this deluded trip and pretend I am in charge of the world. To my surprise, I found that there are quite a few things I would like to change. I'll write them in parts to keep it simple.

Ive always wondered who on earth decided that for every 5 days we work, we should get 2 days off. And why do we follow it generation after generation without even thinking if it is a good idea? 

I get the logic for 24 hours in a day, we cant really help that, and even perhaps for 12 months in a year..But I dont get the 4 weeks in a month and 7 days to a week logic. Can someone tell me the reason? I recommend  that our week should have 6 days and we should have 5 weeks a month. It all works out the same. And it is neater because it fits better into the number of days in a month - because 6 * 5 = 30 days is a lot better than 7 * 4 = 28 days. Right?

Now for, every 4 days we work, we should have 2 days off. Its only common sense that we rest atleast half of the time we work. 

This way, we have 4 days * 5 weeks = 20 days a month of work.
And in the current system, we have 5 days * 4 weeks = 20 days a month of work.

Its the same see?..and definitely so if we were to argue on a minimum number of working days...and this way, our holidays are better-spaced and life will be easier....Nice na? So why dont we adopt this???

There are countries that have as little as 3 days in a week to as many as 20 days. But they are a depressingly small percentage of the world, which largely swears by the 7-day week with 5 working days and 2 holidays...well, not if I ruled :)