Our company considers the Week to begin on Saturday how do I change the Week values to reflect accordingly?
Current Week
Looks like you may be referring to creating a custom Time Dimension. A custom Time Dimension will allow you to set the start of the week along with any date requirements you may have so the visualization looks as desired. The article below goes over creating a Time Dimension.
I’ve included a screenshot below.
You should be able to just change the default one, no need to make a new one unless you need two different ones.