8 Days a week is more of a metaphor.
If you have heard that one beatles' song, it says
"(Something) - eight days a week" I forgot what (something) is exactly.
:P
But it means that they (something) more than the amount of an actual quantity.
For example: I love to pet my dogs 8 days a week.
That means that I love to pet my dogs very much, much more than the amount of a quantity.
I can't really explain the concept very much, but that's pretty much what it is.