380 week of year fix

[joshuacronemeyer]

While I was trying to handle the non-commercial week of the year (which is where the week starts on a sunday). I realized there were scenarios where you could mix commercial date stuff with non-commercial date stuff so had to come up with a consolidated way to handle that. I came up with always converting day of week to a monday start based day of week.

This made all our other scenarios pass without so much conditional logic and seems to handle this mix/match stuff as well.