Sounds like a great idea but getting all countries to adopt it and changing current systems sounds like a nightmare

It'd kill variety, which is essential to life! Imagine you're birthday is on Wednesday... FOREVER! That'd suck!

I like the idea, but a lot of people would have to recompute their birthday, and I kinda don't want mine to change

i doubt it would work. i fear that it will be similar to many units, let it be metrics, heights, distances, temperature or anything similar...

By the way, the Ethiopian calendar has 13 months the last month being of 5 days and 6 on a leap year.

Even if something is logically better than the current way that is do, change is always difficult

Not a good idea at all

Boring. Except for the "mischief" month 13.