Custom rolling 8 weeks

[cfsindorf]

I need to create a custom rolling 8weeks based on the most receint date in a column.  Then group from there in 7 day groupings.

so:
current day 4/29
week eight 4/23-4/29
week 7 4/16-4/22
week 6 4/9-4/15
etc

so if i go to the week level i would see
4/29
4/22
4/15

then day under 4/29 would show me 4/23 - 4/29

Thanks