Fiscal Year End Date changes each year

Good afternoon,

I have an issue where my company uses a Retail Calendar (4-5-4), however, here is the sticky part.  Each FY starts on a different day, always a Friday.

For example, FY2019, started on 2018-12-28 and ends on 2019-12-26.

Fiscal 2018, started on 2017-12-29 and ended on 2018-12-27.

We also have show data relative to the day of the week last year.  In other words, if I am looking at today, 2019-10-28, I would need to compare to 2018-10-27.  I can do that in standard Time Intelligence, the problem I have having is PYTD and PPTD.

Now to my question, any clue how I can determine the previous YTD, PTD numbers?